Radrunner upgrade to TRUE 750w Bafang hub motor

claybear

New Member
When I did this same upgrade to the bafang 750 on a single speed rad the new motor’s axle would not even fit back into the frame! Seems you did not have this problem? Where did you buy you motor and what is the O.L.D spacing? I had to modify the axle shoulder to fit. I did have the same problem with the chain alignment but that was corrected by carefully bending the chain tensioner/derailleur bracket. Really like the added power and speed of the motor, controller and display upgrade. There are a few gotchas but that’s what we get when we modify engineered equipment.
How did you shorten the axle shoulder ? I'm lookimg at doing the same upgrade. I haven't boight motor yet because I've read that motor is 175 mm and rad runner drop out is 167mm.
 

Ccount

Member
How did you shorten the axle shoulder ? I'm lookimg at doing the same upgrade. I haven't boight motor yet because I've read that motor is 175 mm and rad runner drop out is 167mm.
The only reason I lengthened the axle was to accommodate the fender struts. I ended up having the fender on backwards, and in fact there are built in mounting points on the Boltol forks, and all you must do is do some wire bending to match them up!
 

Ccount

Member
I'm sort of curious why you were keen on upgrading to the 750w Bafang motor? From what I understand, this mod adds lots of toque but little to no additional increase in top speed. The extra torque would be useful for hill climbing. But if you're riding on mostly flat roads/trails, I don't see the big advantage??? Getting up to top speed a bit quicker, maybe? (but at the price of hanging on for dear life :))

Same goes for gears. I now own both a RadRunner 1 (RR1) and RadRunner Plus (RR+). The gears on the RR+ offer a significant advantage over the RR1 when it comes to hill climbing. But apart from this, using only the pedal assist settings is akin to switching gears when traveling relatively flat surfaces. If it weren't for steep hills, I'd be content with just the RR1.
I ride on the beach a lot, and in soft sand, it is VERY helpful!
 

Ccount

Member
The only reason I lengthened the axle was to accommodate the fender struts. I ended up having the fender on backwards, and in fact there are built in mounting points on the Boltol forks, and all you must do is do some wire bending to match them up!
It ends up that step was not necessary, i just failed to notice there were available places on the Bolton forks to mount the fender struts. I mounted them to the axle, and needed extra length on the axle.