Manchester eBike Blog

A quick Google search and you’ll easily find loads of information, history and advice regarding crank length for bicycles.  A summary of where things stand today is that most adult bikes sold, tend to come with cranks between 170mm and 175mm in length.
Shorter cranks give you:

• A smaller pedal circle (ie because the radius is shorter)
• Less torque through the pedals
• Effectively a higher (harder) gear
• Most pressure through the joints in the legs, especially the knees
• Better ground clearance

For the purposes of normal human-only powered cycling, if you go too far in either direction from the 170-175mm length, the compromises generally become too great and you end up with something undesirable.

This theory, along with most other long tried and tested bicycle-applied theories, has been carried over to pedal assist eBikes.  In the short term this is necessary, simply to get things to market – it works, why change it?  But as we start to look more and more into new eBike specific technologies, products and ideas, it’s worth questioning pretty much everything and that certainly should include telemetries, ergonomics and bicycle geometry.  The long chain stay debate is another of these and covered in a previous blog entry here.

So how might different length cranks benefit eBikes?  Well, firstly some of the problems caused by 175mm cranks are noticeably worse on eBikes; but also some of the downsides of shortening the cranks are much less of an issue on eBikes.

The biggest benefit of short cranks for off road eBike use is ground clearance.  Going uphill over rough terrain on a full suspension eBikes is really where they can shine the most – but due to the nature and legality of pedal assist eBikes, in order to get the power, the cranks have to be turning.  Anyone who’s ridden a full suspension eBike over rough terrain will know that pedal strikes are common – and it can be more than mildly annoying, it really can lead to broken/bent components or worse – injuries.  To compound matters, the bigger the eBike’s rear suspension travel, the worse the problem gets as it allows the bottom bracket a lower potential height from the ground when the suspension compresses.  Early remedies to this problem seemed to be either raise the bottom bracket height – which has terrible consequences on the bikes handling in other situations; or fit rear shocks with super hard climb settings on the damper dials – again not ideal as this basically makes the suspension stop working.

So why not shorten the cranks?  Well the usual logic is that this requires a big increase in pedalling torque, but with eBikes – not so, because the vast majority of power and torque are delivered by the motor, not your legs.  So how short to go?  Well the test options are fairly limited as to what’s available.  The shortest currently-available adult crank length is 160mm.  That’s enough to make a significant difference, but you can actually go slightly further by fitting kid’s bike cranks which go as short as 152mm and still have normal fittings for the crank centre axle and pedal thread – ie they bolt straight on without modification.

So I’ve been riding 152mm kids cranks on a 160mm travel full suspension eBike for a whole year now and I’m happy to report that its simply better and with only minor compromise.  No more pedal strikes and the bike can happily be pedalled over much more bumpy terrain.  I say “with only minor compromise”, but to be honest there are a couple of minor points I should add.  Firstly, super short cranks require a higher saddle height in order to get a full leg extension.  That means your body as a whole is higher during seated pedal-climbing, but its really not a big deal.  It does mean that the bigger travel seat droppers start to become more necessary.  And secondly, it can make your knees feel a bit odd after long rides.  I don’t fully know why, but it just feels like being in an airoplane seat if you don’t stop and bend your knees fully every now and then.  I think it’s made worse sometimes when I’ve been climbing over particulalrly difficult terrarin with the saddle at half extension – just to get my body lower and ease my balance.

So overall I’m a convert and I don’t plan on refitting the standard-length cranks.  I don’t think I’m the only person either.  I’ve noticed that manufacturuers are starting to spec 160mm cranks on new bikes.  Possibly even more telling is that Bosch have also added a software update for running short cranks.  It’s optional and easily removeable with the Bosch diagnostics kit.  As for what it actually changes, I don’t know the exact numerical differences, but from the feeling in the pedals and how the bike delivers power, I’d say it simply lowers the amount of rider input necessary for the motor to deliver its full payload.  You still only get 75Nm and 600-ish Watts at max output, but it feels easier to get the motor to deliver that.  I’d say that the cadence speed to power delivery remains about the same – I think to change this would require more than a simple software update.

I’d even consider trying shorter still cranks, maybe even 120 or 100mm cranks should they become available.  This could even allow an eBike’s geometry to feature abnormally lower bottom bracket heights – which is generally understood to lower the height of weight (or “centre of gravity”) and make the bike more dynamic, easier to balance and manoeuvre.

I think it’s going to be interesting to look at many other areas of the eBike that have been inherrited from the standard bicycle – what else can be changed and improved?  I think I’ve said in a previous blog entry that eBike development is still in its infancy.  Given 10 years, I think eBikes will look drastically different to their normal bike counterparts.  A few obvious changes to come are tyres, saddles and transmission – all of which need a hollistic redesign for eBikes.

If you haven’t ridden an eBike on a huge, flat beach it might sound boring and uninticing.  Admittedly that was my assumption too, until I decided to do it simply to get the kids off to sleep in the buggy – but it’s surprisingly exhilarating.  I think a lot of my initial trepidation was because I know how hard it is to ride on sand, even tidal zone sand is way harder than tarmac – but then I remembered this is an eBike, so no such arduous labour is required!

Obviously you can get specific bikes and eBikes for riding on sand (and indeed snow) called Fat Bikes, but I’m just talking about a normal city style eBike.

Whether it be on the tidal sand or on the parellel coastal tracks, taking the eBike with 2 kids in the trailer was a great idea and provided not only a fun activity for the day, but a useful transport alternative for an otherwise traffic filled road network around Devon in the summer.  Plus it has the added bonus of having a lunchtime cheeky pint without worry of trouble with the law or personal safety.

Odd title, I know.  And I guess it’s not even one that might initially pique your interest, but the more general point I’m alluding to is eBike geometry….

The bicycle is well over 100 years old now and it’s fair to say it’s been through many, many iterations and experimentation, including some pretty extreme niche cases, but in general it has steadily evolved over the years.  In more recently years the biggest technological advancements have been in construction materials and techniques, making bikes lighter, stiffer etc.  In the various genres, a bicycle’s geometry has often been seen as a far lesser important component.  We’re so far down the line with bicycles, that I think a lot of people assume that we’ve been through the experimental phases and surely now we must be getting close to the perfect geometry.  I think to some degree this has some truth in road and commuter based bikes.  They’ve existed the longest and roads haven’t changed significantly.  There’s also been some amount of limitation to road bike’s  geometry imposed by the UCI (Union Cylist International – cycling’s overlord governing body).

An area where the final perfect geometry is far less known is mountain bikes.  It’s even true to say that historically, MTB geometry hasn’t been a big consideration of manufacturer’s or consumers.  The large brand’s marketing machines have preferred to push new suspension designs, frame materials and often simply the paint scheme or drive-chain specification.  That was until around 8-10 or so years ago when the development of MTB frames got to the more flatter curve of what’s possible with available technologies – nowadays you could even say it’s plateaued.  Bikes aren’t getting significantly lighter, stiffer, faster, and more efficient purely based on how they’re made.   I guess it’s like any bubble – it grows for a while, but inevitably bursts at some stage.  This caused a dramatic slow-down of new whole-bike sales.  A trend began to emerge where consumers would renew their worn transmission and tyres, but stay with their frame and fork much longer – because the “new” versions weren’t as radically better year on year, like they used to be.  The cycle industry’s initial reaction to this was good – it powered a rush of development into components instead of the frames.  Suspension, dropper posts, brakes and tyres all came on a lot in a seemingly more accelerated way.  But it left the big frame brands ultimately, frustrated.  “How can we force new whole-bike sales?”  they shouted in boardroom meetings!  Well, I believe that’s where 29ers came frame….. And what d’you do when that bubble bursts?  Well, change the axle and other standards to make older components obsolete – and recently I think this has caused contempt for manufacturers from consumers.  The veil of apparent honesty and care for the consumer had been exposed as bull**it, instead replaced by a much colder version of reality.  Well this is capitalism – get over it.  Brand’s, just like banks only care about growth and profit – without which, they plunder.

Aaaanyway, without wanting to digress too much, a much brighter reason to buy new MTB frames is starting to emerge: geometry.  The big brands have now (finally) started to experiment with properly different and better geometry.
I suspect a similar sequence of events probably also happened to road bikes in the past – but I was only born in 1980, and I don’t know a huge amount about the history of road bicycles.

So how does this affect eBikes?  Well, eBikes are still in their infancy as a genre at all, with the eMTB genre being younger still.  eMTB’s have only really existed for about 5 years.  Many of the early eMTB’s were either bodged normal bikes with heavy wheel motors or eMTB’s that went straight from drawing board to production and shop floor, without any testing at all, such was the rush to get them to market.  The outcome of this is that eMTB’s (even now), are still seen as an iteration of the normal bike version.  Many brands produce both an electric and non-electric version of the same bike, so much of the geometry is carried over from the standard versio.  It is this, which I think is currently the biggest short-coming of eMTB’s – their need to resemble the geometry of standard MTB’s.  The biggest example of this is in chain-stay length – see, I got to the title point eventually!

There is a trend at the moment for MTB’s to have very short chain-stays.  I’m not expressing my own opinion towards this, but it is generally accepted that short chain-stay on an MTB can create a more “playful” bike that is easier to turn, pop and generally mess around on – it makes a bike have desirable handling characteristics at slower speeds.  Short chain-stays certainly make it easier to wheelie a bike!

Like any number on the geometry chart, there are always downsides to chasing a lower or higher one.  In basic terms (and this is a huge generalisation) when you extend or decrease a geo-number the bike will go better/worse when riding uphill and create an opposite effect when going down hill.  The truth is more complicated than that, but you can at least get the idea that to affect one area positively, there is usually a compromise somewhere else.
In the case of short chain-stays, as mentioned they can create some positives, but some of the downsides can be to make the bike less stable at speed going downhill and also that with a riders weight closer to the rear wheel pivot point – ie the axle – it can lead to the bike tipping over backwards when climbing steep/technical trails uphill, also known as “looping out”.

This is exactly where the difference of eMTBs to standard MTBs is prevalent – but so often overlooked.  So much of an eMTB’s pleasure and advantage is in their ability to power up the hills – if you put short chain-stay on them, all of this is lost.  It’s a common oversight, because mountain bikers would normally assume that short chain-stays should be so desirable.  A recent example of this is Rocky Mountain’s new Altitude Powerplay eMTB.  RM were so keen to develop an eMTB with short chainstays that they had to make their own motor – because most other eBike motors won’t allow short chain-stays due to clearance issues.  It was their biggest hurdle to conquer – and they’ve managed it.  The Powerplay has 425mm chain-stays.  That is MEGA short for a 27.5″ wheeled bike, even a non-electric bike would struggle to achieve CT’s that short.
Sadly as you can read in this review of the bike on Pinkbike, these short CT’s are unfortunately the bike’s biggest weakness – because it makes the bike rubbish at climbing.  Extract:

“The downsides of the Powerplay’s trail bike geometry are its very short, 426mm chainstays and the slack, by modern standards, seat angle. Both make for a wheelie machine when ascending, which leads to extra fatigue on climbs as the rider must constantly battle to keep the front end down. Luckily I have good hip flexibility, but many riders suffer here and will struggle to keep the front wheel on track and the bike on-line. It is easy to float the front wheel over obstacles, but much more easy to start to loop out or simply stray off the track. The light front wheel can be remedied slightly by using the Ride-9 adjustment chip on the shock linkage, but there are some disadvantages, namely, lifting the rear of the bike and steepening the steering geometry. The difficulty found in climbing this bike is trail based, if you want to shuttle yourself up a road to pin the downhills, then what I’m describing here is almost a moot point, but climbing and descending challenging trails is where the eMTB fun begins.” – Pinkbike.

And this is a conclusion also well exemplified in the other direct by the KTM Kapoho LT (that I have on test at the moment and will publish my thoughts of soon).  The KTM has enormous chainstays, just shy of 500mm.  If you’re a mountain biker who is aware of modern geometry trends, this number would utterly terrify you.  For many, seeing that number alone would mean a definite “no thanks” before they ever lifted a leg over the bike to try it, because that would just be terrible to ride, right?  Well they’d be wrong.  The KTM’s big CT’s are character defining and possibly it’s biggest strength.  They make a bike capable of climbing literally ANY technical ascent (coupled with the large tyre’s unflichable traction).

For me, I do think the KTM is a little too far along the scale of chainstay length and it does slightly detract from the bike’s downhill handling, but my point over all, of this blog entry, is – that eBikes should not be thought of simply as a normal bike that gets to the top of the hill for you.  To think that is missing the point; you’ll miss all the fun you can have effortlessly sailing uphills; you may also end up being disappointed by eMTBs if all you’re hoping for is a self-propelled bike.  eBikes should be thought of in their own right – they are not simply bicycles that pedal themselves.

A pragmatic approach blog entry, to answering some of the eBike haters comments and concerns.  eBikes and especially eMTB’s are still causing quite a lot of negative reaction, but is it fair or justified?
….so, I’m going to start by splitting the hater comments into 2 distinct categories:
Firstly, there’s the reactionary to anything new being “gahh, just take it away, make it stop” etc.  These tend to be not-entirely-logical, Daily Mail, pitchfork waving people.  I’m going to call this category “New is bad“.
And secondly there are many people who have real concerns.  These I’m going to call “Genuinely concerned“.

So I’ll start with the “New is bad” type comments and I promise I will at least try to be sensible…

Its cheating.
Let’s start with the google dictionary definition of cheating.
“to act dishonestly or unfairly in order to gain an advantage“.  Well, in this respect I can, kind of, a little bit, understand.  I mean, eBike motors are close to silent these days and more and more are trying to hide the battery inside the frame, making an eBike look very much like a normal bicycle (with varying degrees of success).  But I’m not exactly sure that’s being dishonest?  Electric motors are quiet, just because they are, not really by specific design.  Plus, you’d put batteries inside a frame for the same reason we put cables inside the frame – it just looks way neater.
And the other definitions don’t really apply.  You can’t “cheat” on your wife with an eBike.  Well, not in the traditional sense anyway.
If it isn’t a race, then how are you cheating?
I think what is really meant by “cheat” is the more obvious lack of effort required to ride an eBike, therefore you’re cheating yourself of the health benefits of riding a bike.  But what if health benefits aren’t your main intention?  What if the main reason you ride is to have fun, take in the views, get some country air or more practical reasons like to get to the shops or commute to work?  Or even rehabilition reasons, like a hip replacement etc.
I understand that people can feel a bit annoyed that their ride was aforded to them by a ton of hard work.  Not just on that ride, but on all the other rides that built up enough fitness to go on that ride.  The time, the effort, the sweat, the panting, the suffering, even the equipment, the clothing, the hyration pack, the really expensive breathable waterproof – you don’t need any of that to ride an eBike.  I can see how people find that annoying…… mmmmmm, but it’s still nonsense.  I mean, I bet there were plenty of horse guys that were pretty annoyed when Henry Ford started producing his horseless-cart.  Do we remember them with empathy and understanding?  No, we don’t remember them at all.

It’s a motorised bicycle, therefore a Motor-bike.  Why should they be allowed the same rules and reg’s as bicycles?
It seems to have taken about 40 years too long, but we finally seem to have realised, as a global society, that bicycles = good.  They help to solve 2 huge problems we have on planet Earth, (plus others) those being a huge population of obese people; and terrible air quality due to a tranport system that is reliant on burning fossil fuels.  So any way of reducing combustion engine journeys has to be a good one, right?  This is why eBikes are regulated under the same laws and rules as bicycles.  Because we absolutely must get away from car journeys.
Putting eBikes under the same banner as bicycles helps them become the accepted norm, whether they be ridden on or off road.

And let’s not forget that all of the obove “new is bad” comments can all be answered with – “It’s no one’s business what I choose to buy or ride, as long as it’s legal and not anti-social”.

The geunine concerns:

Cycle access worries
At present, there is no UK trail centre, national park, council, postcode or private cycle network which deferentiates between eBike and Bike usage.  Ie anywhere you can ride a normal bike, you can ride an eBike – as far as I’m aware.  In fact, many trail centres encourage eBikes and the new trail users that bring them.  Just like normal-bike riders, they bring their wallet, buy cake and coffee in the cafes, put money in the parking meters and don’t reach higher max speeds than normal-bike riders.  It is a worry that more cyclists of any kind bring additional burden on resources, additional wear on the trails and increase risk of incidents simply by increasing the volume.  But guess what, we all have the same rights to access.  Just because more people are able to utilise that access doesn’t mean it’s unfair.

In Europe we have huge access to the countryside.  In the UK a lot of our access rights  to the countryside can be traced back to the 1932 “Kinder Scout 80: Mass Tresspass” http://www.kindertrespass.com/  Have a look here or on Wikipedia if you’re interested, but basically it opened up the British countryside to hikers on footpaths and byways etc.   The 1980’s brought us mountain bikes, which as “non-motorised vehicles” are allowed on byways, bridleways, cycle paths, disused railways and oddly enough, footpaths (although the common misconception is that mtbs are banned from footpaths – technically, they’re not entirely, but it gets complicated).
Conversly to all this lovely countryside access we have here, over in the “land of the free” in America, their access rights are drastically limited.  There is no “right to roam” or equivalent.  In terms of countryside access, they are anything but “free”.  Access for MTB’s there is terrible and seems to be getting more restricted, not less, because the American version of “free” usually means “free to those that can afford it“.
So when you see comments online about eBikes worsening the problem for access, a huge amount of these originate from the US.  And I think from their point of view, it’s a lot more understandable.  It’s already a very sensitive subject, so I can see why adding eBikes to the problem fills them with dread.  I do understand that.  I think a lot of the access fears originate in this way from the US.

Trail errosion
Mountain bike trail erosion has been discussed for as long as MTB’s have existed.  After a quick scan through Google there seems to be plenty of evidence either way as to whether MTB’s cause more trail erosion than horses or walkers.  Within that topic, there now comes the question of whether eMTB’s cause more or less trail erosion than standard MTB’s.  For this more specific topic, there is much less evidence either way.  What I’d say from my own experience, is that riding an eMTB involves much less pulsed pedal inputs and the power is delivered in a much smoother way, so the theory is that this would reduce trail erosion

If eBikes become the norm, future generations will grow up having never ridden a normal bike.  This is counter productive to the obesity argument.
This is probably one of the few (maybe only?) argument I struggle to disagree with.  I’ve even noticed my own belly start to increase in size during times of higher frequency useage of eBike use and as a fairly commited, lifetime cyclist I do think that at times, it has made me lazy.  I’d also say the the majority of eBike users I’ve seen on the roads and trails aren’t the normal slim cyclist physique.
But, well it’s just unavoidable.  Not having to invest such a huge chunk of time into the fitness is a double edged-sword.  Most of me just ends up thinking – I don’t care, this is so much fun.  But maybe I’ll regret that when I’m 70?

Looking at things with a little perspective, I really think that the amount of online negitivity towards eBikes has drastically subsided in the past 12 months and I expect this trend to continue – but there is a long way to go before eBikes have true acceptance.  Plus I guess there will always be those hardcore internet trolls that just love to shout down their keyboard if they think it will cause a reaction.
I certainly think that the legality of de-restricted eBikes will play a large part in the public’s attitude towards eBikes as a whole.  Even though they should be categorised differently – in general, they won’t be.  Just like the recent case of a pedestrian death caused by an illegal bicycle, no-one remembers the technicality of the bike lacking any brakes – people will simply remember that a cyclist killed a pedestrian and was then a dick about it – I think this story could so easily have been an illegal eBike, instead of an illegal bicycle and it would do terrible damage to the overall image of eBikes.  I’d even go so far as to say something like this, whether more or less serious, is almost an eventuality not a possibility.

The KTM Macina Eight P5 is the 3rd long-term eBike I’ve ridden and replaces last year’s KTM Venture Vienna Di2.  Those 2 bikes are pretty similar, so a comparison is unavoidable.  The only significant difference being the motor: the Vianna being a Shimano STePS motor; and the Eight is a Bosch Perforance motor with 500 Wh battery (hence the “P5” in the bike’s title).  So the on-paper performance between the 2, you might expect would be fairly different in terms of the torque each motor delivers – Shimano STePS produces 50Nm and the Bosch Performance is normally 63Nm right?  Well not so on hub gear equipped bikes.  Shimano won’t allow eBikes equipped with their Nexus hub gears to be spec’ed with motors that exceed 55Nm (on any brand of bike), so the Bosch Performance motor is down-tuned a little to meet this requirement, although it’s max power remains at 600Watts – the same as a normal Performance Bosch motor.  That somewhat evens up the torque gap between Shimano STePS and Bosch Performance motors, enough so that torque difference in reality is barely noticable.

Aside from motor differences to the Vienna, the Eight has a more modern looking frame with a semi-integrated battery.  It’s motor attachment bracket is drop-cast in sand and the frame as a whole has a slightly more angular, purposeful look.  It also rides slightly stiffer – in a nice way, although there is still a touch of rubbery-ness that comes from a mono-tube step-through frame.  Its the same slight flexiness that you feel in an open top car in comparison to an equivalent hard top.  Its really not an issue on a bike with the Eight’s remit – that being comfy city hybrid, with the occasional longer trekking ride.

There are a couple more subtle differences to the Eight too.  The battery is 20% larger capacity than the Vienna, which I guess is nice, but I never found the battery lacking on the Vienna, but then I rarely do single rides over 30 miles, which either would manage easily.  What is an improvement is the way the battery is charged: on the Eight the battery can be charged either on or off the bike.  I find charging the battery on the bike to be a little more convenient.
The bike lights are operated on the Eight with their own button, which I also prefer – the Vienna’s were operated by holding down one of the gear shifters for 3 seconds.  Again it’s only a subtle difference, but I definitely prefer the Bosch method.
The final noticeable difference between the 2 eBikes is that the Vianna had an electric Di2 Nexus gear hub operated by 2 buttons and the Eight has a mechanical Nexus gear hub operated by a twist grip.  Both are 8 speed and share identical gear ratios.  To be honest I expected to really miss the Di2 shifting of the Vienna more than I do.  The Di2 shifter I’d say is slightly nicer to use, but not hugely.  It doesn’t actually function any better than the mechanical shifter and I never really liked the auto-shift function of Di2 anyway so disengaged it.

So in it’s own right, the KTM Macina Eight is perfectly spec’ed, with a substantial kickstand and robust mudguards.  The lights are nicely integrated into the frame and fork and are powered by the main battery; they’re surprisingly powerful too – I never felt under-lit.  The pannier rack is also nicely integrated and I used it nearly every time I rode the bike – for carrying one of my kids and for 100’s of other duties too.
Some people may turn their nose up at Magura rim brakes, but in function they are actually superb.  They never overheated and don’t cause much wear to the rims.  Being hydraulic, they require no maintenance, just some adjustment to allow pad wear.  Replacement brake pads are also cheap and easily available.

The usual KTM attention to detail is there too, with reflective strip tyres, height/reach adjustable stem, basic-but-functional suspension fork & seat post and ergo-fit handle bar grips.  I even like the bell, which manages to be loud without sounding aggressive – ping!

The Eight is only available in step-through frame type, but KTM have scores of similar alternatives if you’d prefer a more traditional double-diamond frame.  Step-through eBikes are not likely to improve your street cred’ (hah!), but from a purely practical point of view, I see little reason not to use this frame style for sit-up hybrids.  One of the step-through frame’s best attributes is it’s size versatility.  This KTM Macina Eight has a 46cm frame, which is as small as they come, but can be ridden by my 5’6″ wife or myself at 6’3″ all day long without discomfort.

The retail price of the KTM Macina Eight I think is extremely competitive.  You can pay quite a lot more, like a Trek Super Commuter or Haibike SDuro Cross and get no improvement in spec.

Those looking for a >10 mile commuter/get-about eBike should look no further.  It’s versatile, extremely robust, will destroy hills that would normally see riders sweating profusely and has all the kit, from new, that you’ll ever need.

Improvements?  Well, this bike is a 46cm which, as I mention is as small as the Eights come.  That’s fine if you’re 5’5″ or taller, but smaller riders would probably struggle, especially as the suspension seatpost can only be lowered so far.  So a smaller frame size would be a good addition.  And finally, maybe some slightly wider tyres might add a bit of extra comfort? Maybe….

It’s worth pointing out that details of the updated 2018 KTM Macina Eight are already out.  The new model is basically identical, but with additional options including a fully integrated frame battery option and a disc brake option.
The 2018 Macina Eight is due to be built in the KTM factory in February – orders are being taken now.

The power transfer of eBikes via electrical assist motors, from the crank motor to the rear wheel, is one of the biggest variants of different eBikes.  It’s one of the main contributors to an eBike’s overall character.  Each type of transmission has specific applications, some more versatile than others, but there is quite a lot of choice, so it’s worth understanding the pro’s and con’s of each and how it will affect the type of eBike you may be looking at purchasing.

The 2 main categories are derailleur (aka “mech”) and hub gears, but there are also combo systems of those 2, plus some other slight variants.

Derailleur systems.
If you’re really new to derailleurs, it may be worth a little bachground reading on Wikipedia.  Put as simply as I can, a derailleur uses a chain with a spring loaded, adjustable jockey wheel that moves the chain over a cassette of varying sized chainrings.

This derailleur is adjusted (ie moves the chain onto different chainrings) at the handle bar.  They are indexed with audible “clicks” between gears either with a thumb/finger shifter or a twist grip.  Twist shift tend to be used in conjunction with hub gears; finger/thumb shifters tend to be used with derailleurs.  Both of these types can be cable (aka “mechanical”) or electronic (the most common of which is Shimano’s Di2 gear shifting system, which has hub gear and derailleur variants).

Derailleur cassettes commonly have 8, 9, 10 or 11 chainrings – but more is not necessarily better.  They all have similar gear ranges that change the gear ratios of around 0-400%, but with fewer chainrings there are just less in-between gears.  SRAM’s new eBike specific groupset for example has only 8 cogs on the cassette and they are not a cheap option – instead they are thicker and designed to change gear under extremely heavy torque loads.  The more expensive cassettes use different materials, construction techniques, coatings and different levels of machining that include subtly shaped shifting “ramps”.  Shifting ramps often look very subtle, but make a huge difference to the gear shifting performance, accuracy and speed.  For example, Shimano’s top end 11 speed cassette uses hard-coated steel and titanium cogs mounted to an aluminium carrier or “spider”, where it’s clearly seen a huge amount of very intricate CNC machining.

Derailleur strengths and weaknesses
Probably the biggest strength of derailleurs is their ability to change gear during high load on the chain.  It can make a few cracks and bangs during shifts, but it’s little more than noise.
Derailleurs are also reletively very lightweight and cheap to buy – mostly due to the vast numbers in which they are produced.  The derailleur was invented around 100 years ago (see the Wikipedia link earlier) and it’s evolved a lot over that time.  Today’s derailleurs can handle a lot of mud, crap, neglect and water, but they are still relitively sensitive to set up.  They really need to be attached to a very straight piece of metal from which they hang (hence the term “hanger”).  Their other main weakness is longevity.  The derailleur itself can last many 100’s even 1000’s of miles, but the chain and cassette can wear very quickly – which need changing when worn as they rely on a spring loaded jockey (ie the derailleur) in order for the chain to properly mesh with the chainrings.  When the chain and chainrings become worn, the chain will skip over the chainrings under high torque.  A chain can become worn in as little as 100 miles if the bike is used in a lot of mud, water and in hilly areas.
Another strength of derailleurs is their efficiency as it’s purely a chain transmitted power delivery, therefore power loss is less than 1%. Its also very immediate power transfer and not rubbery.
And finally, it can be seen as a weakness of derailleurs that changing gears requires cycling the transmission (ie pedalling) so you can’t change gear while stationary or at the very last second.  Personally I don’t feel this is a huge draw back as you do become used to pre-empting gear selection with practice.

Derailleur applications on eBikes
The biggest use of derailleurs on eBikes is simply when there’s a high torque motor.  Shimano for example won’t allow their hub gears to be spec’ed on Bosch’s Perforamce CX motor as it produces too much torque for the hub to handle – but derailleurs are perfectly fine for this application.  They also tend to be spec’ed on all eMTB’s – a lot of this is history and tradition, but also because of some of the downsides of the alternatives are pretty bad – read on….

Hub gears
The most obvious difference with hub enclosed gearboxes is that they are completely self-contained.  Even the hubs don’t look particularly different, so they basically appear to be a single speed drive system.
Hub gear systems for bicycles were also first implemented around 100 years ago – see this Wikipedia link.
In eBike applications they generally have 7, 8 or 11 different gears (14 gear hubs also exist for bicycles, but are not generally used on eBikes as factory spec, mostly due to high cost).  By far the biggest manufacturer of eBike spec’ed hub gears is Shimano, ie well over 90% of all hub gears spec’ed at factory on eBikes are Shimano, which all feature planetary style gear mechanisms.

The handle bar mounted shift-mechanism options are the same as derailleurs: finger/thumb shifter, twist grip shifter or electronic button.

Hub gear strengths and weaknesses
Hub gears biggest strength is the low-maintenance aspect.  The suggested service interval for a Shimano Nexus 7 or 8 speed gear hub for example, is 10,000 miles and even that is conservative.  Realistically, hub gears should run pretty much un-serviced for the lifetime of the eBike.  Because the system is completely self-contained, it is isolated from all weather conditions, mud, grit and other contaminants.
Likewise the chain on hub gear eBikes tend to last for huge maintenance intervals, this is because the chain can be much thicker and also because its impossible for the chain to slip over the chainrings as it’s a fixed system – not one that relies on tensioning the chain via a spring loaded derailleur.
Sadly, that’s pretty much where the strengths end for hub gears; there are quite a lot of downsides….
Wheel removal – hub gears require a sliding frame drop-out in order to tension the chain.  That means the axle needs to be held in place very tightly, so they use axle nuts, not a QR axle, so you need spanners to remove the rear wheel and it’s not particularly quick!  It also makes them tricky to use with disc brakes – it’s not impossible, but frames must have some system of drop-out that is both horizontally adjustable (to get the chain tension) and will also place the disc brake caliper in the correct place over the disc rotor.
Rear suspension compatibility – with a suspension frame, the distance between the rear axle and the crank axle varies as the suspension moves up and down it’s travel – it is not fixed.  In order for the chain to stay tensioned, a jockey wheel is required.  This is where derailleurs offer a secondary use of their spring loaded jockey wheels.  Adding a jockey wheel to a hub gear system is an extra faff needed to adapt them to suspension frames – which also leads me to the next downside…
Weight – Hub gears weigh quite a bit more than derailleur/cassette systems, this is especially bad on suspension frames as increasing the unsprung mass in relation to the sprung mass, decreases the suspension’s sensitivity to bumps.  Don’t over-analyse that – you can read endlessly into it and just end up confused, but just remember that unsprung weight = bad.  It can make a bigger difference than you might expect.
Low Torque only – as mentioned earlier, hub gears can’t take infinite torque.  The cogs inside them are pretty small and the axles they turn on will eventually bend and snap.  Shimano only allow 55Nm max capacity on their hub gears, so even Bosch Performance drives have to be “down-tuned” from the usual 63Nm (although max power output remains at 600 Watts)
Problems are not easily solved – despite their low maintenance, problems do occasionally happen, and when they do, it can be difficult to diagnose and fix.  A  mid-ride hub gear issue will almost certainly mean that the eBike ride is over – there are rarely quick “trail-side” fixes.
Loss of efficiency – not much of a big deal this, as most of the power comes from a motor/battery (ie not your legs), but whenever power is transferred by cogs (and not chain alone) there is a power loss of around 5% as a minimum.
The final downside of note is the gear shift of planetary hub gears.  Gear shifts on the whole have to be done while the transmission is not in motion – ie you have to briefly stop pedalling.  You can use this to your advantage, for example when coming to an unexpected or ugent stop after travelling at speed – you can change gear while completely stationary, back through the whole range, in order to set off again easily.  If you try to change gear while pedalling and there is even a medium amount of strain going through the transmission, it can miss-shift or “grind” and fail to engage; it can also cause premature wear inside the hub.
Cup & cone bearings – due to the majority of hub gears being manufactured by Shimano, that also brings with it the dreaded cup& cone or “open” style of axle bearings.  This has caused much debate over the years and Shimano has stuck to its guns on the matter and simply will not recognise the advantages of a removable “cartridge” style bearing.  Personally, I think Shimano are plain wrong on the matter, but it doesn’t change the fact that for the foreseeable future hub gears are stuck with open bearings – which, when the cups become worn, are not replaceable.  That’s fine if they never get mud inside….

Hub gears applications on eBikes
As I’ve already established, hub gears don’t really suit eMTB’s, so they’re only fitted to city hybrids and trekking eBikes with lower torque output motors.  It suits eBikes where the user doesn’t want to be bothered with maintenance (that’s most urban commuters and holiday/distance trekkers), especially for high mileage users.  It very much suits roads with traffic lights too, due to the ability (and necessity) to change gear while stationary.  It also suits hire fleets and it’s a more robust system overall with close to zero wear and little required maintenance.

Combination hub and derailleur (SRAM 30 speed)
Just a quick note on this, as there’s only 1 combo system that I’m aware of – that being Sram’s “Dual” hub, which contains a 3 speed hub gear with a 10 speed casette, thereby creating 30 possible combinations.  Realistically, it’s application to eBikes is largely pointless as it extends the useable gear range way beyond the assistance provided by a legally restricted eBike.  What tends to happen with Dual drives is the cassette is used as normal, but the hub gear is left in gear 2 for 95% of the time.  It’s still something customers who haven’t owned eBikes before ask for though – as they’re afraid that 8, 9 or 10 gears won’t be enough.
Well, most cars have 6 gears – do you wish they had 18 so they would more easily cruise at 150mph?  No, me neither.

Nuvinci electric and mechanical
Again just a quick note on this specific brand of hub gear (as I think Nuvinci own the patent) – it’s a hub gear, but NOT a planetary gear system.  Instead it runs on the variable circle diamters of the edge of a ring of sphere.  Here’s a video explain it, but if you struggle to understand that, well its kind of similar to cone gears.  The main advantage is the ability to change gear infinity finely AND during high torque load.  It’s a great idea in principle, but has a bit of a rough history with reliability issues.
It’s also worth noting that this system is what Continental have incorporated into their new eBike motor and integrated gearbox.  I wrote about them recently here.

Summary and future
So there you go – that’s the long version of eBike gear system choice!
In the future, I think all eBike components will steadily evolve away from being shared by standard bicycles and this is especially true of gear and transmission systems.  There simply isn’t currently an ideal gear system made for eBikes and there really could be – and needs to be!  All the current options are simply adapted bicycle parts (even if slightly beefed up), which are not designed for the long-term, high torque eBike motors already available.  It’ll take time not only for parts to be developed, but also because the emergence and acceptance of eBikes is still very new and fragile.  During the next chapter of eBikes, I think they will need to continue to closely resemble bicycles in order to gain acceptance and become “normal” – so parts sharing with bicycles will continue for a while yet.  With time and more sales of eBikes, when they do eventually become the norm, this is when eBike specific components will start to become proper and specialised.
I think Continental’s integrated gearbox and motor that I tested and wrote about last week is a pretty big step forward.  I hope to see other systems like this soon…

I knew about the huge car and bicycle tyre divisions of Continental, but I must confess that I was completely unaware that they also manufacture many other car and electrical parts including turbos and looming.  In fact, it turns out that Conti’ have R&D departments in all kinds of things…..

So my ignorance met with quite a shock to hear that Conti’ had not only got an eBike drive in the pipeline, but it’s actually pretty close to large-scale production manufacture, with early units hitting German shop floors within this calendar year.  Although I don’t know which frame brands will be using them as OEM spec’, I suspect it will not be a small minority.  Conti is a huge company and I doubt this is a “toe in the water” type roll out.

So I went to the Birmingham NEC Cycle Show to see for myself and again to my surprise, they even had a few test mules.

What I know so far….

As for technical data, there’s most of the tech-spec on the Conti’ website here, so I won’t copy/paste it in.  The big news, and I mean REALLY BIG news is – this will be the first large scale production of an eBike motor with a self-contained gearbox. I’ve been utterly dumbfounded as to the absence of this concept for literally 10 years.  It seems SO obvious!  I really don’t understand why it’s taken until late 2017 for someone to bring a geared eBike motor to market.  I know Shimano have something similar in development, but as far as I’m aware, that still only makes 2 brands – and you can be sure Shimano will take their sweet time to bring theirs out, as is normally the case with Shimano.

It solves so many of eBikes current problems.  It centralises the weight; reduces unsprung weight on suspension frames; keeps all the mud out; and generally just seems a much better idea to integrate the gearbox and motor into a single unit.  It’s also a significant step away from parts borrowed/adapted from bicycles – and to me, this is the important bit.  Current bicycle transmission is designed to transfer around 100 Watts of power for most the time, with normal human output peaks (ie not Sir Chris Hoy) of around 500 Watts.  eBikes, which remember are combined with human efforts, transfer roughly 3 to 4 times these values – it’s just way beyond what a normal bicycle chain and chainring can withstand for long periods.  Imagine making your 150 horsepower VW Passat into a 600 horsepower beast – how long would that transmission system last?  I’m guessing, not very long at all!

I know from my own experience that eMTBs when used in extreme terrain (eg the Peak District!) can stretch a chain within litterally less than 100 miles.  That’s about 4 average rides.

I guess the other, not so big news, is that the Conti’ eBike uses a Nuvinci gearbox and a belt drive.  The quickest way to explain this “Continuously Variable Transmission” system is simply to watch this short video.  In simple terms, it’s kind of like cone gears – there is no break between gear shifts and its effectively infinitely indexed, so the drive doesn’t need to let up at all during shifts.  The only reason I say this isn’t massive news is that Nuvinci have had these hub enclosed gearboxes for quite a few years now, so the technology itself isn’t new – just its application.  Likewise the beltdrive isn’t a new idea.

So – the test ride

The NEC Cycle Show eBike test ground was hardly much of a challenge for the bike, but it had a short slope to climb and I was able to gain at least a basic feel for things.  And overall I found it very impressive.  In use, it’s not actually very different to other general experience of eBikes.  I’ve ridden countless eBikes, including those fitted with Nuvinci hubs before, but it was good to see that there wasn’t anything odd or awkward feeling – it just felt like a fairly standard Bosch Performance motor.  I wasn’t really able to get a feel for power delivery or peak output.

Conti’ only had a few eBikes on show, and weren’t able to include a full suspension eMTB that had the integrated gearbox.  I think in the long run, this should be one of the best applications of the system.  A system isolated from mud ingress and also with an extremely lightweight rear wheel will surely make a killer combo for offroad riding and personally I can’t wait to try one in real-world conditions!

Shimano introduced the original STePS system around 4 years ago, but realistically, bikes with it were being produced and appeared on shop floors during the 2015 model year.
Last year I spent a full 12 months with this red KTM eBike and, unsurprisingly I absolutely loved it.
I originally took reciept of the Vienna in January 2016.  It was my first experience with both the Shimano Steps drive and also the Di2 hub-gear.  All bikes from KTM arrive in a huge box and come 99% assembled, ready to go.  All I had to do was plug the seat post in, turn the handle bars and screw the pedals on, oh and charge the battery of course!  All of which is super basic.  The gears are set up, the brakes alligned and the tyres are inflated.
All bikes from Manchester eBikes do also have a standard PDI check too, just to be sure.
From unboxing many other KTM’s over the years, I knew that their Austrian factory build quality is one of their best strengths.  Everything from the welding quality, paint finish and parts assembly really is second to none.  KTM clearly take great pride in their work and it shows.

Sizing and fit.
The frame size on this bike is a 46cm.  It’s the smallest available for the Vienna and only a few other KTM eBikes have the option of smaller frames, all of which have smaller wheels than the Vienna’s 700c’s.  Now I’m 6’2″ and KTM’s sizing chart suggests I would best fit a 56cm, a whole 2 sizes bigger than the 46, so you may think this is an odd choice.  Well the reasons are simple: my wife has to be able to ride it (she’s 5’6″) and the smaller sizes are always much more useful for demonstration purposes.  However, I’ve ridden other 46cm eBikes before and know that, because the power comes from a motor, not really one’s legs, you can comfortably ride a much smaller bike than you might normally choose otherwise.  The 46 has been fine for me all year.  I’d advise the same to others too really – if you’re at all in doubt about size (for a hybrid type eBike), go smaller.

The Shimano STePS drive
The Steps drive on the Vienna is European and UK legal, giving 250W nominal power; assisted pedalling upto 25kph (about 16mph); and 50Nm of torque at maximum assistance.
It has 4 assist modes (zero, eco, normal, high) and although 50Nm of pull is plenty for the bike’s intended use, I did tend to leave it in ‘high’ for the vast majority of time.  Maybe I’m lazy?  But you just get used to the bike doing the work!

Battery capacity / range
The Vienna’s battery is a 400W/hr unit.  How far you get from a single charge obviously depends how much you use the juice.  In real terms, a full charge is enough for as much cycling as you’d want to do in a single day.  I never got less than 20 hilly miles per charge, but in the Peak District, I never got the 50+ miles the catalogue indicated.  One point I would make though is that most journeys don’t start on 100% battery, so I did run out of juice a few times over the last 12 months.  The problem is having a regular run, like my child-nursery run, which used about 15% of a charge each time, so it doesn’t really seem necessary to charge it, knowing there’s 85% remaining.  The problem comes, when I’d done a couple of these and then wanted to do a 35 mile journey the following day.  This is just a habit or planning issue though and wouldn’t be solved by having a bigger capacity.

Components
Everything is there from the start and fit for purpose.  The Vienna comes with really bright front and rear lights – easily bright enough to light up green lanes in the pitch black night; a sturdy kick stand; the mudgaurds are integrated with the pannier rack which makes them both very sturdy – hence the addition of a child’s seat, which I never felt nervous about; and a chain guard.  No upgrades were necessary (apart from said childseat I guess).  It’s worth noting that the lights run from the main battery and require a pretty insignificant amount of power, so I ran them pretty much all the time – I just thought why wouldn’t I?
A small mention should also go to the extremely adjustable stem, which I set to maximum height and shortest reach giving the bike a super relaxed position for the rider.
I must admit to being a touch sceptical about the Nexus Di2 8 speed gear hub.  I was worried about the gear range being wide enough and didn’t really see the point of having electrically shifting gears (as opposed to cable).  The range is decent and the top gear (8th) is perfect for flat cruising at maximum assist speed, but I live in the Peak District and because some of the B lanes are extremely steep, I did occasionally find that 1st gear would struggle with the 1:3 hill gradients.  That’s a seriously steep hill though and I should stress that I never once actually stalled, but I did have to pedal quite hard up these.
The Di2 electric shift was amazing and a real surprize.  It’s digital and therefore never goes out of allignment or miss shifts.  The difficult part to explain is that it only really makes sense when you try it.  Its a fantastic and polished system.  It changes gear much better under pedal strain than the cable equivalent too, because the computer knows you’re changing gear and can tell the motor to momentarily kill the power, just enough for a smooth shift.
It still has limits though and shifting during extreme crank power can lead cause a problem.  It was always quickly remedied by a brief pause in pedalling, but this can occasionally be annoying.  So it’s easier to negate the issue all together by always doing a brief pause during gear-shifts while pedalling hard.  It isn’t a problem at all for most riding conditions.  The only function of the Di2 shifting I never really used was the Auto-shift function.  I just think I’m too much of a control freak – I want to choose the gear I’m in, because I can see what’s coming up ahead – a computer can’t.

Issues and niggles
There’s nothing major to report really, but I do have a few recommendations to the factory – so it’s handy that I know the head of R&D at KTM Bikes.

• Firstly, the on/off button is only on the battery.  Not a huge problem, but it is one of the few differences the 2017 Vienna’s have improved upon (the new ones have on switch on the head unit).
• The battery has to be removed to be charged – again, another improvement on the 2017 Vienna’s.  Not a biggy, but removing the battery to charge every time is a bit of a faff and part of the reason I ran out of charge due to not starting with a full battery, as mentioned earlier.
• The handle bar buttons aren’t particularly comfortable.  You only really notice this when using walk mode, as holding it for more than 60 seconds starts to hurt your thumb.

Summary
It looks like a rather long list of niggles above, but really they are all very minor.  Overall this has been a fantastic product which has genuinely improved mine and my family’s lives.  We’ve done countless family rides (obviously using another eBike as well), shopping trips and general shortish journeys.  At the start of the year I vowed that I really wanted both myself and my wife to try as hard as possible to stop all sub-5-mile car journeys, instead using this KTM eBike and I really think that we’ve made significant impact on those journeys.  If I were to put a figure on it, I’d say we’ve managed to cut out a good 70% of sub-5-mile car journeys and enjoyed every minute of doing so.  The lack of required maintenance has really aided the bike’s readiness to just get on with it.  Other than changing the brake pads and 2 chains (due to wear, they never snapped) the only maintenance the Vienna recieved is a rare wash.
eBike rides are effortless adventures that are invigerating and eye opening.

Initial impressions of the 2016 KTM eGnition are not uniformally “Wow, what a pretty bike”. Hah, it’s true to say that she ain’t a thing of beauty.  Instead, I think the bike looks agressive, chunky and industrial.  There’s a definate feeling of “early version” to this eBike, as demonstrated by it’s side-lining for 2017 to just being one of KTM’s S45 bikes.  The standard eGnition is now replaced by far sleeker looking eMTBs from KTM, like the Macina Lycan below.

However, that’s pretty much where the negatives end, because to ride – this bike is an absolute riot.
There is a ton of power on tap, lets make that clear.  The Bosch Performance CX drive gives upto 75Nm of torque.  To put that into some normal context, a VW Passat 2.0 TDi engine produces only 3 times more torque (Source).
That’s a third of the power for pulling a 2.2tonne family estate car.  It’s a lot.  It’ll pull you up ANY hill, in any conditions, over any terrain and I really tested it at times, having ridden through axle deep bogs, snow drifts and up seriously steep Lake District bridleways.  I am still yet to stall the bike’s power, in fact I think the chain would snap before the motor stopped turning, which thankfully never happened!

OK, so it’ll get you to the top with ease.  What about how it rides?  Well, it’s harder to talk about than you might think.  You see, the grin factor while riding the eGnition uphill never wears off, at all.  Not even for a minute.  There were times when the only reason I got out of breath was from laughing so hard at how this bike just demolishes hills.  I remember riding some hills just thinkng “this can’t be legal, it’s just not right” because it just seems too good to be true.  Like there’s going to imminently be some huge string attached or downside.  And you wait for it, but it never arrives.

Anyway, when I did finally find time to think about the bike’s overall handling and demenour, it came as no real surprise that it too is really great fun.  The KTM is a lot more manourverable than the weight suggests.  It’s actually extremely playful and great at pushing tight muddy turns.  I think it’s best attribute is actually aided by the additional, but very central weight – which is smashing through rocks at max speed.  The suspension tracks with great sensitivity and feels glued to the trail.  The long chain stay does make popping the front wheel up a little harder though and manual-wheelies are really difficult to start and even harder to maintain.
I think the eGnition’s greatest attribute is simply its versatility and eagerness to just ride up, over or through anything.  Its like a daft spaniel dog, with tons of energy, a lust for life and just keen to go wherever you want….. at maximum speed, with minimal effort.

Limitations
Probably the biggest issue while riding cross-country on the KTM eGnition is lifting it over stiles.  It’s heavy, there’s no way around that.  And although it can and will be lifted over stiles, by the time you get to the 5th or 6th one, it starts to get pretty tiring.
The other more obvious limitation is the battery capacity.  The battery stat’s quoted in Bosch’s paperwork clearly aren’t for bikes ridden on what I used it for.  When used for proper hardcore offroad riding, pretty much constantly in “Turbo”, the range is little more than 15 miles realistically, which can be done in close to an hour, so for longer rides I had to be careful to use more of the “Sport” and “Tour” modes to stretch out the range.  If I was careful like this, range is much closer to 35 miles, even in muddy hills.  Not fantastic, but it’s certainly enough to have a really good time.
As well as cross-country rides, I also rode at quite a few downhill tracks.  Look closely at the featured photo above and you’ll see an “Annual pass” sticker on the fork leg for the excellent Farmer John’s DH Bike Park in Marple.  This is really an area where the bike excells.  Pushing up DH tracks like this is really hard work, especially when it’s muddy, and it’s fairly normal to expect around 6 full runs in a whole day, maximum.  Well not on the KTM.  It’s hard to believe how many runs I could do in just a few hours.  In fact, you probably wouldn’t believe me, so I’ll just say that after 25 I lost count.

The final limitation of the bike is the rear shock.  Fox XC air shocks have come on leaps and bounds in recent years.  I think the latest EVOL air chambers show the best of this and are rediculously plush and well controlled for their weight.  However, 160mm rear wheel travel is a lot to ask from a relitively tiny 50mm shock travel.  Generally, anything over a 3:1 wheel/shock travel is asking a lot, but the issue is made worse by the extra suspended-weight of this eMTB.  I put the maximum sized volume reducer insert inside the air chamber, but it only had minimal effect.  For big-hit DH tracks I ran the shock at close to it’s maximum stated allowed-pressure (240psi).  This was enough to stop bottoming out while still keeping it plush and active, but it got pretty hot at times.  To be fair, doing repeated DH runs is a bit beyond the bike’s remit and I think it’s fair to say the bike handled it well considering I’m 90kg’s.  It’s not really a DH bike and I certainly took it to it’s limits more than a few times!

Things I changed over the year:
Firstly, it’s tyres.  The stock tyres that come with a KTM eGnition (Schwalbe Fat Albert/Rock Razor) are great for what the bike is designed and what most people are likely to use this bike for.  They’re a great trail tyre combo.  They grip most things ok and as long as you pump them up pretty hard and don’t ride super rock stuff, they’re fairly reliable and sturdy.  However – for me, they were the first thing to go.  On an eMTB I have no regard for rolling resistance or see any point in keeping tyres light-weight.  I just want maximum grip and no punctures, so after the 3rd puncture I fitted a pair of Schwalbe ProCores and some much more aggressive Continantal Trail King 2.4’s.  That added quite a lot of weight to the bike, but weight that was only noticed lifting the bike over stiles and fences – on the trail I didn’t notice the extra weight at all.  What I did notice and appreciate is the grip of good, soft compound, large volume tyres and complete safety of Schwalbe ProCores (Google it if you’ve never heard of them, but simply, its a dual chamber tyre system that genuinely illiminates punctures, even at super low punctures).  ProCores aren’t cheap, but with an eMTB it’s a perfect match.

The second and probably biggest change I made to the bike is the headset.  The stock headset is fine, but I wanted to stretch out the bike’s head angle and wheelbase, so fitted a -2 degree angleset from Works Components and a shorter 50mm stem.  The headtube on the eGnition is a straight 1.5″ unit, so allows enough room to do this, even when using tapered steerer headtube forks.  It changes the head angle to around 63 degrees.  This really turned up the descending speed of the bike and along with the shorter stem, really compliments the longer than normal chainstays by moving the rider’s weight much further backwards.

Summary
As I’ve mentioned, I took this eBike so much further than it’s intended design remit – and that’s because it dares you to.  I absolutely loved it.
I think most of the factory spec is perfect: the hugely powerful brakes; the gear range; the motor power; battery capacity; the components and wheelset.  Its all there and ready to tear the crap out of the trails.  The things I changed were relitively minor and only necessary if you want the bike to cater more purely to gravity and speed.  All the basic ingredients are already there for a versatile and hilarious adventure bike.