Hello!

I got a BTWIN RockRider 540 some years ago and use it for some light trails, but nowadays mostly just roads. My region is very hilly and has multiple >10º hills, which are perfectly fine for cars, but not really for bikes 😅

Since I’d like to start doing more things in the city center (which is itself also on the hilly side), I was considering either getting an e-bike or converting mine. I’m more inclined towards the latter option, since I really don’t need another bike (already have an extra all-terrain bike for trails and a vintage road bike), it would just be a waste of materials and, from what I understand, money. I’m really not sure where to start looking for appropriate conversion kits, so thought to ask here :)
My budget is flexible, but I’d like to keep it under 200€.

Any comments are appreciated!

  • Avid AmoebaEnglish
    6·
    3 months ago

    That price will be very difficult to meet. For that money it’ll probably have to be an AliExpress special. Get a front hub. You probably want a torque arm but I don’t think you’ll find any in that price range. You can get away without one if you run the motor at low power, like 250W. Unfortunately I don’t think you can get a non-hazardous battery anywhere close to that price range. Perhaps look for LiFePO4 (LFP) battery since the chemistry is inherently safer and it’s cheaper to make. It’s heavier than standard Li-ion.

    Otherwise I’d get:

    • Bafang G311
    • Compatible Bafang controller with torque assist capability. The lowest wattage will do
    • Bafang display
    • Bafang torque sensing bottom bracket
    • Good quality but smaller battery. E.g. 300-400Whr.

    With all that said, steep gradients can kill geared hubs so a direct-drive hub or a mid drive like BBS02/HD might be better suited. Most DD hubs are more powerful so you’d either have to use torque arm/a or run it at low wattage. In general aluminum frames can’t handle a lot of torque at their dropouts without spreading or cracking. The rear dropouts can handle 500-700W when the nuts are correctly torqued. You can read about that on ebikes.ca.