Is there a rear wheel hub motor that fits aluminium 125mm frame?
Hi, new to the forum. I have a aluminium Felt cruiser frame that I'd like to convert to electric. I'd prefer to use a rear wheel hub motor since it provides better traction. Since the frame is aluminium I can't widen it. Does anyone make a good quality rear motor that will fit in this frame with 125mm wide rear dropouts?
What are you performance requirements ? *( rider weight, area/terrain, desired speed on level ground ) .. battery voltage etc.. and budget ?
I have a couple Crystalyte 4 series front axle motors and some side covers with freewheel threads, the front axle is 100mm, the side cover and a couple washers would make a 125mm easily enough... these are no longer made.. but have a reputation for being the most silent motor available.
Otherwise, most rear motors are 135mm so you would have to strech the frame a bit, i realize it's aluminum but most frames will flex enough for this without too much trouble ( done it lots )
I used a Q100 on the rear of a single speed bike. That motor is designed for forks from 100mm to 135mm. It comes with spacers spacers built into it to get it to the standard mountain bike spacing of 135mm, and my single speed is 120mm (mine is "fixed gear track bike" style rear dropout). I went to a hardware store and bought a "bearing" (basically steel or plastic hollow cylinder) to replace one of the ones that came with the hub and give me the spacing I wanted. You can use washers or nuts to fine tune spacing if you need to.
However, I'm thinking the Q100 is really 130mm when I measured it. It fits pretty easy "out of the box" on my 120mm aluminum frame. So, you really can take it just as it is and use it with a 126mm frame.
Bending the frame by 2mm each side is trivial. Its not hard to get the Q100 a bit under 130mm.