The Beginners Guide to Buying an eMTB

Outside of the main cities, eMTB is the hottest ticket in ebikes. If your goal is to be able to go up any mountain in sight (Queenstown), ride longer and higher without shuttles (Rotorua) or simply keep up with your stronger, fitter, younger or less-injured mates, an eMTB might be for you. It’s a great equalizer for a couple too. You now have similar powers.

By eMTB I refer to generally full-suspension bikes with a mid-drive motor, that are intended for ‘proper’ mountain biking on singletrack and/or rutty, rocky, challenging terrain. On rail trails, almost any ebike with a teeny bit of front suspension will do. Hardtail eMTBs are also a viable option for touring and light MTB riding.

An eMTB should have a mid-drive motor. Why? Because it take mass away from the axles and allows your wheels to move properly over terrain. The weight is in the centre of the bike (the pedal area) and towards the front, which is your preferred weight distribution anyway.

It should also have a torque sensor, NOT cadence-only sensor. Why? Because you control the power through your pedals.

Motors and Batteries

Here’s the thing: all the eMTB motor systems are quite good and in 2019 models are typically limited to 32km/h (do check, even on an eMTB 25 is annoying). They have their own character and marginal pros and cons. Don’t buy a bike solely based on what motor it has. You wouldn’t buy a car like that, would you?

Motor System Battery Unique features and benefits Negatives
Bosch Performance CX 625Wh or 500Wh eMTB mode is great. Most popular. Good service coverage nationally. MY2020 is much improved: lighter and more compact, more power and torque, great eMTB mode
Yamaha (and Giant) 625Wh, 500Wh, 400Wh (Reign can take an extender) Nicely profiled torque curve. The Giant motor is ‘better’ than the stock Yamaha PW-X. Non-Giant versions top out at 110 pedal cadence. PW-X/Giant sounds a bit ‘grindy’
Shimano e8000 (improved EP8 coming) >500Wh Most torque. Nice display. A bit noisy but no more than a Bosch or Giant. EP8 said to be much quieter.
Brose (and Specialized) 460-700Wh Quiet. Good torque. The Specialized version is slightly tweaked and can be tweaked more via Bluetooth. No shift sensing. Support for Brose (other than Specialized) is not as good as other main brands.
Bafang Max 400-600Wh Quiet. Good torque. Often unlimited top speed so can be used for commuting. Some manufacturers spec them with low-power controllers.

Ok, now that we’ve got that out the way, we’ve got a bike to buy.

The rest

I’m generalizing, but the reason you are buying this expensive beast is to have fun on some trails. There is a vast difference in ‘feel’ between bikes, and you want the one that matches your style of riding. Some considerations upfront:

  • Longer travel suspension is better, and longer than you need is less of an issue on an eMTB than on a regular MTB. So a 140mm travel eMTB is entry level in my opinion (though the 125mm on the Hypersonic didn’t feel undergunned in Auckland). But don’t be ridiculous, and if you are of smaller stature you might still find that shorter fits you more comfortably.
  • Wider tyres are better. Most modern MTB have 2.3-2.4″ tyres, and eMTB should have 2.6″-2.8″ tyres (though 2.4″ on 30mm 29″ rims is also OK). Wider gives you more grip which you’ll want given the extra weight, and adds comfort too. Expert riders might argue this point.
  • Some things you can easily change on your bike later on if you want. That includes tyres, saddle, handlebars, pedals etc. Some saddle choices on stock bikes are horrid, try and get this right before you leave the shop.
  • Some things you don’t want to change, or simply can’t. So, in descending order of importance:
    • The frame geometry must suit your style of riding and fit you. Right now specifics of geometry are beyond the scope of this guide, but hopefully over time through reviews we’ll build up a bit of a guide. Your trusty shop should be able to advise about head angles, chainstay length and so on if you ask (see Notes on Geometry below)
    • The suspension is expensive, contributing $2000 or more of the cost of a good MTB/eMTB. Go for the best components you can. It is often where compromises are made. If you are and always will be a conservative sort of rider, it might matter less. A suspension seatpost is not a substitute for rear suspension no matter what anyone might tell you (although useful for a bit of comfort if you have a hardtail). Suspension setup is crucial, and depends on how you ride, how much you weigh and where you’ll be riding. I prefer a bit softer than recommended because I am a bit soft…
    • Wheels matter. Typically the more you pay, the better wheels and tyres you will get. Look for tubeless ready rims and tyres on a quality rig. A good set of wheels can cost up to $4000 for carbon fibre. Good wheels are robust AND comfortable, and provide a good mount for your tubeless tyres. Why tubeless? Comfort, traction, lower rolling resistance and better puncture protection especially in rocky or rooty terrain.
    • Brakes are helpful too! Don’t get mountain bikers started on what are their favourite brakes. Most are fine, some are better. You want the front brakes to be more powerful than the rear. You want a main brand so that replacement pads are easy to get (and because of your speed and weight you’ll go through more pads than an acoustic MTB).
    • Gears and Drivetrain aren’t as important on an eMTB as on a lightweight XC or road bike, but you want robustness. The SRAM system offers 11 or 12 gears and a wide range. Shimano is good too. Ebike-specific shifters shift one gear at a time to save your chain.
  • A dropper seatpost is nice if you are planning on riding rougher stuff, but not essential. It can be added later quite simply for $300-$600.

My usual disclaimer

  • You generally get what you pay for
  • You want to buy from somewhere that displays good knowledge of their products and will provide good support – you will need that support at some time
  • You really should ride the bike, ideally on your sort of terrain. Most decent bike shops can access a demo bike for you.

Notes on Geometry:

  • 470mm seems to be the default chainstay length on 130-160mm travel eMTBs and offers the sort of stability in technical uphill stuff most eMTB buyers expect. Much shorter and the bike will feel a bit more edgy and ‘poppy’ (eg Haibike Xduro AllMtn/ Haro Shift is 455mm, Specialized Levo 459mm/ Kenevo 443mm, Pivot Shuttle 437mm). Much longer (KTM Kapoho, Trek Powerfly) and it’ll likely be more stable and planted allowing you to stay seated. Needs to be looked at in combination with seat tube angle (74deg is typical) and head angle too. It depends on your riding style and abilities which style you might prefer.
  • 66-67 degrees is the head angle most eMTBs are going for, though longer and slacker is the trend. Steeper (68-70deg) will give you sharper handling at the expense of downhill poise, and vice versa.
  • It’s more complicated than it might look on paper. You really need to try the bike and see if you like it. It is a big investment. ‘Best’ isn’t necessarily best for you (eg Pivot Shuttle)

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