An Introduction to Electric Mountain Bikes

Rather than call this ‘A Complete Guide’, as EBR did in its articles on mid-drives and hub motors, we figured there couldn’t really be a ‘complete’ article to electric mountain bikes. The choice today in terms of different designs of e-mtb and the ever developing technology is wider than ever, so no guide is ever going to cover all the brands and options out there. Instead we take a look at the main areas potential e-mtb buyers might want to think about.

This article aims to demystify the jargon and leave you with a clear picture of all the e-mtb options out there. If you feel like you are missing out on the fun by not exploring the world of e-mtbs you probably are, so read on to get better acquainted with it!

The Basics

Like traditional mountain bikes, e-MTBSs come in three main types based on suspension:

Hardtails

Hardtail e-mtbs have suspension only in the front fork. You will notice the benefits of front suspension on arms, shoulders and head, especially on longer rides as well as when ‘dropping off’ rock steps and the like. They tend to be chosen for riders who travel on ‘cross-country’ style trails, enjoying a day out in the hills away from civilisation, as opposed to thrill-seeking adrenalin downhill riders who invariably need a full-suspension e-mtb to maintain control of the bike at fast speeds downhill.

One compelling reason to go for a hardtail might be that, given other components of equal quality, they cost less than a full suspension e-mtb for the obvious reason they don’t need all that complicated and expensive engineering that comes with good quality rear suspension. Lack of rear suspension can also mean hardtails are some of the lightest e-mtbs around.

Full Suspension

So-called ‘full-sus’ e-mtbs have rear suspension in addition to front suspension, allowing the rear wheel and rear forks to move up and down to take the shock out of bigger bumps and when dropping off rock steps. Budget e-mtbs may very well not work very effectively and only end up adding weight so be very cautious if considering such a model.

High-quality full-sus e-mtbs cost considerably more than hardtails and poor quality full-sus models but can certainly add a lot to the ride experience especially if you expect to venture over much rougher and hillier terrain. As well as being favoured by adrenalin junkie downhill riders they also reduce fatigue and make riding more comfortable for many other kinds of off-road riding. As an older e-mtb rider I particularly appreciate the comfort advantages of a full-sus e-mtb for rougher trails.

Rigid

Rigid e-mtbs offer no suspension system at all other than that found in the cushioning effect of seat and tires. For lighter trails they can be a good option. However, they are a rare breed in terms of e-mtbs as rigid off-road models are catered for plentifully in the hybrid/trekking e-bike category – the hybrid category bikes often come with more ‘user-friendly’ features like pannier racks and mudguards. So-called gravel bikes are also made for moderate off-road riding and designed for speed both on and off-road, with racy frame geometry and drop handlebars and they also cut into the need for a rigid e-mtb category.

One of the few rigid e-mtbs out there is the Islabikes eJimi, picture above, designed for older riders who want to tackle moderate off-road terrain and want a very light e-mtb with low gearing for easy pedalling.

Steel or Air? How Much Travel?

Suspension technology generally also comes in two types, a wound steel spring, or air spring forks. Air spring forks will tend to be lighter and easier to adjust and give a smoother ride but are more expensive. There can also be a significant difference in ride quality between bottom end, very cheaply made steel spring suspension and better quality models. If you can afford it air suspension will certainly provide a smoother ride.

You will also see references to ‘long-travel’ and ‘short travel’ suspension. This refers to how much the suspension travels up and down by – put simply, the bigger the bumps you are going to travel over and the greater your speed the more suspension travel you need.

Front suspension starts at around 100mm travel on true e-mtbs (it’s often less on trekking style e-bikes) and short travel goes up to 120mm.  120-160mm is considered ‘middle ground’ and provides huge trail capability – certainly enough for most riders of average ability – whilst e-mtbs with 160mm of front suspension travel is usually considered long travel, with plenty of movement for big downhill impacts and jumps at speed for the highly skilled. Check out the following Trek Rail video which gives a nice clear explanation of all the features found a typical long travel, high-performance e-mtb:

Rear suspension, or ‘shock’ for short, tends to follow the amount of suspension on the front forks. You might see two figures quoted – 1.5” to 3” is a typical range for ‘stroke travel’ or how much the shock can compress whilst you may also see a figure similar to the front suspension travel which will be how much the rear wheel itself moves.

Motor System Technology

Meet the Beasts

These are usually the e-MTBs that feature in the online videos; you know the ones, showing pro-level riders hurtling down twisty and rocky trails and doing seeming impossible mid-air maneuvers before landing the bike smoothly. They are most often full-suspension.

The most aggressively performing e-mtbs naturally use the most powerful motors with Bosch’s Performance Line CX dominating in this category. Some brands like Cube, Moustache and Riese & Muller use Bosch mid-drives across their entire range of e-bikes. Other top of the line mid-drives that feature on these hugely capable machines include the Shimano Steps E8000 (soon to be superseded by the EP8 system), Brose’s Drive S and Yamaha’s  PW Series X2.

In a league of it’s own is the Flyon system, clearly the most powerful mid-drive out there, though naturally it adds weight and $s to the price tag! It uses a totally different pin-based power transfer system compared to more traditionally-geared mid-drives that rely on cogged teeth to transfer. If you think you need the ultimate in climbing power this is it!

It is worth singling out Haibike here as they offer a great range of high performance motors across their large range of e-mtbs including the Flyon, Bosch Performance Line CX and Yamaha’s PW-X2.

Moustache’s 2021 Samedi Trail 29 range of full suspension e-mtbs are also worth picking out. Whilst the range continues their use of the latest Bosch motors and batteries in the form of the 2021 version of Bosch’s Performance Line CX allied with a whopping 625Wh frame-integrated battery, it also looks to open up their high performance to as wide an audience as possible through their easy riding characteristics promoted by stable, large wheels and a relaxed riding position.

High Performance for All

There are a number of mid-drives used on e-mtbs that give plenty of performance but are aimed at riders who perhaps want a slightly gentler experience on the trail and don’t want or need to spend big, big bucks on top-performing e-mtbs.

The Shimano E7000 is a slightly less powerful and cheaper mid-drive than the very successful, top-performing E8000 and is used on a handful of e-mtbs like the Thok MIG 2.0 and the Voodoo Zobop E. As you can see below the Thok doesn’tsacrifice too much in the way of performance:

eMTBS Lite

Fazua’s Evation removable mid-drive is found mainly on e-road bikes and lighter urban models but if you don’t need the full-on power of a larger mid-drive and value a lightweight e-mtb over a truly powerful one then this system is worth a look.

The Raven² hardtail range from Focus weigh 36lb-37.5lb / 16.3kg-17.kg and with 100mm front suspension travel look a great choice for slightly easier cross-country trails. Another Fazua-powered hardtail is the UK’s Kinesis Rise range – they have heavier stated weights at 42lb-43.5lb / 19-19.7kg but sub-44 lb / 20kg is still light for an e-mtb and they have more suspension travel at 130mm.

If money is no object but you want a full-suspension lightweight e-mtb then the Specialized Turbo Levo SL must surely be near the top of your list; Specialized’s own tiny mid-drive rewards fast pedal speed in particular with plenty of power. There are plenty of options and price points within the Turbo Levo SL range but sub-44lb / 20kg is the order of the day – absolutely outstanding for a full-suspension mid-drive e-mtb. To see how it compares to the most powerful Bosch e-mtb motor check out this instructive video.

LaPierre’s sub-44lb / 20kg E-Zesty model is another full-suspension lightweight contender and uses the Fazua Evation drive; it’s worth noting that Fazua upgraded the software on the latest version of their system to give more power in the top assist mode.

eMTBs on a Budget

There are some good value, high quality full-suspension e-mtbs in addition to the Voodoo and Thok models singled out above. The BULLS Six50 EVO AM1 is hardly budget priced for US buyers but represents great value for money for the top-performing full-sus spec. More reasonably priced though with a much lower spec than the BULLS is Voltbike’s Enduro (though more for easygoing trails than full on singletrack).

Current standout full-suspension buys in the UK market include the Haibike SDURO FullSeven 1.0 at £2249 and this Decathlon Stilus model at £2699.

Hardtail e-mtbs with top of the line mid drives start somewhere under US$4000, Trek’s Powerfly 4 and  Bulls Twenty9 EVO1 both being good examples. If you can live will a little less power in your mid-drive the Scott Aspect Eride 950 offers great value for money at US$2599.

Crossover Off-Road Models and Demographic Specific Models

Most of the models featured so far are ‘classic’ emtb designs with a conventional frame and no ‘extras’ such as lights, mudguards or kickstand. But the extra motor power of e-mtbs means the extra weight of these additions isn’t the hassle to carry around off-road it once was. What’s more the whole new demographic that e-bikes are popular with has meant the growth of ‘crossover’ designs that blend some aspects of other genres with the ‘purists’ e-mtb, as riders look for e-mtbs that are capable of more than just providing a great quality ride over demanding terrain.

First up lets take a look at ‘adventure’ models – e-mtbs that means you can ride all day over rougher terrain but with the advantage of being able to carry food, extra clothes for when the sun starts setting and maybe even camping gear. Riese and Muller make some standout models in this regard and their full-suspension Delite range can be equipped with rear pannier rack and and wide off-road tires. Check out our full review here.

Whilst Riese & Muller are unashamedly very premium priced e-bikes as they feature top line components and incredible build quality there are cheaper adventure style e-mtbs out there. The Scott Axis Eride EVO features a full component package including lights and rack whilst Cube’s Stereo Hybrid 120 Pro Allroad looks a superb machine for long weekend off-road trips.

For those less flexible than the average rider, be it through age or for any other reason, there are also a growing number of step-thru models including Cube’s  Nuride range  and the super Riese and Muller Nevo GX.

For women many brands now have women specific-models so check out the offerings from Cube, Haibike, and Liv (whose range include some great price points including for full-sus e-mtbs).

Kids aren’t left out the action either, with growing range of models from the likes of Ben-e-Bike, Cube and kids’ bike specialist Woom. If you don’t think young kids have e-mtbing ability check out this video from Austria’s KTM Minime model..

Finally, for that truly fully loaded off road trip why not seek out a full suspension, off-road capable e-cargo bike.

Stay tuned for more e-bike news and reviews and thanks for reading!

-Rich