Sprocket Hub Adapter

[Bubba57-chevy]

I'm new to the forum, and the motorized bicycle world. You guys are top notch. My question is in regard to a c/hug adapter. I'm currently working on a 1979 Schwinn Heavy Duti. The wheels are new from wheel master, 26" coaster brake, alloy rims and stainless spokes. Beautiful wheel. However the hub, measured with a micrometer, is 1.75" in diameter. My plan is to put a 4 stroke/Grubee transmission and want to use a hub adapter on the rear wheel. I cannot find a 1.75" hub adapter. Will a 1.8" be ok? Maybe shim with rubber? Grind or sand the mating surfaces of the adapter? Do I need to look at a different wheel? TIA.

 

[Bubbaq]

I hope the 1.8” works, I ordered one.

 

[YetiWoodz]

Sometimes part dimensions are rounded up, so likely 1.75 and 1.8 are the same.

Do beware of the coaster brake wheel though. From my experience with them on a motorized bike is not fun. For me, the brake shoes somehow jumped over next to each other instead of across, the bearings next to the coaster brake arm get destroyed, and the coaster brake arm's rectangular notch gets rounded out due to grinding, and the wheel is forced loose and not turning straight. I don't know exactly which one happens first, but most of the time, they all happen together. I don't know the exact cause, but it is possible that it is just due to me not torquing the nuts enough. It usually starts going wrong after braking hard with the coaster brake, but it also happens when barely using it. So my advice is put removable thread locker on the 2 fork nuts and torque it 20-25ft lbs, don't put lots of force on the coaster brake when using it, and have another brake or 2 such as rim brakes and disk brakes, disk brakes being the best option.

It's good to have another brake regardless. If something does go wrong with your wheel, you can convert it to a freewheel by just taking out the brake shoes, that's what I did. But watch videos on how to take apart those wheels and put it back together before doing that.

 

[Bubba57-chevy]

Thank you YetiWoodz.