Newbie

[Dino50]

Hi all I'm new on here. I'm considering converting a mtb to electric. Ideally a pedal assist version. Could anyone explain the pros/cons of mid v rear installation please. I'd like to keep the bike as light as possible for when it's being used by pedal power only. Thanks in advance Dave.

 

[vfr400]

Hub-motor
Pros

• Cheap
• Reliable
• Low running costs
• Power doesn't depend on gears
• You can keep your gearing

Cons

• Weight towards the back is not so good for exceptionally steep hills, like you get for serious off-road stuff. It makes the bike wheelie.
• Power has a fixed range of speed, so you have to choose one that gives its power at your modal riding speed. Too slow, and it runs inefficiently; too fast, and the motor maxes out, so no power
• More thought, planning and adjustment to fit than a mid-drive

Crank-drive
pros

• Weight in the centre gives sharp handling for tight off-road stuff.
• Power depends on gearing, so you can get the power at any speed and climb exceptionally steep hills with the right gearing.
• Easy to fit.

Cons

• Faster wear and more chance of failures with the drive train. Any drive train issues will leave you stranded.
• You have to be in the right gear all the time, which makes riding more frantic and less relaxing.
• More expensive
• Higher running costs due to wear and other drive train issues.
• You normally have to change your front gearing - no triple chain rings

Some people will mention the difference in efficiencies. My tests show that that's false.

Some people will mention the extra difficulty in taking off a hub-motor wheel, but that isn't an issue. You fix punctures with the wheel on and if you fit a puncture resistant tyre, you'll probably never have to take the wheel off in the lifetime of the bike. Mine's been off once in 6 years, and even them, it didn't need it.

I always advise people to get a hub-motor for riding on the road and light trails, and a crank motor if you want to do serious off-road riding.