incorporating bafang mid-drive into belt / shaft drive bike with gearhub

davidneedsabike

Finding my (electric) wheels
Sep 12, 2015
15
0
68
This appears to be the most efficient combo, but I have no idea how to achieve it, particularly with one eye on the wallet - suggestions please

I am very taken by the internal geared hubs, so welcome suggestions to some of best alternatives

Pretty sold on the 750 or new 1000 bafang mid-drive

Seem to make sense to have belt or shaft drive - welcome input as to how best these can be married to Bafang and where best to source a bike with most of the work done / specialists who can perform the more difficult remaining conversion elements

strikes me that Dynamic shaft drive should buy in Bafang type motors and incorporate into their drives, presumably the freewheel being in the rear hub can only help - this would be a super neat solution - doing away with all exposed gears front and back also oily chain and vulnerable deraileur - since the motor could be directly geared into shaft, losing the belt would also make it more compact ...win, win, win?
 

flecc

Member
Oct 25, 2006
52,763
30,349
...Pedals would still need a freewheel to stop pedals turning when motor engaged?
Crank units already have a front freewheel to avoid motor overrun driving the pedals, so that's already taken care of. However, most hub gears can be vulnerable when handling both rider and motor input, since the manufacturer's torque limits can be exceeded then, so perhaps not always the ideal choice they might seem to be.

Also bike shaft drives are not as sealed as they might appear to be. The most common one only has an outer cowl over the rear bevel gears, leaving them still exposed to gathering dirt and grit. It has to be that way to allow rear wheel removal.
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Geebee

Esteemed Pedelecer
Mar 26, 2010
1,256
227
Australia
From comments on the net about the 750 w unit and my using a BBS01 I would stick with the chain for a few reasons, its easy to carry several quick links and a chain breaker to fix a breakage, you can even carry a short length of chain as well if you wish, if you change gears to keep the dive spinning fast the load on the chain is much less and should not be an issue (treat the drive like you are pedalling for power), the other killer is trying to change gears under high load and not blipping the brake to stop the motor.

A broken belt cant be Fixed without replacement, a shaft drive will have the right angle drive as a weak spot and a hub gear system may fail with the higher wattages, plus a shaft drive is less efficient to start with.

Just my 2 cents worth.
 
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