26” Beach Cruiser conversion rear hub

I’m wondering if anyone can shed a little light on the 135mm standard all the rear hubs seem to be sized to. I have a single speed I want to convert and the space in rear for the wheel is only 110mm. Is this going to be an issue?

you have a few options.

you can use a front motor in the rear, which won't have a place for your chain.

you can do the above, but modify the rightside cover to hold a freewheel. there's a few threads about this if you're interested in the idea.

you can look for folding-bike motors. some of them will have narrower axle shoulder spacing, possibly as little as 110mm (maybe 120mm). http://ebikes.ca had some at one time.


or you can use the front hubmotor in the front, and leave your rear wheel alone.

or you can use a middrive, or a friction drive, dependign on your needs and the bike design.



if this is like most of the beach cruisers i've seen, it doesn't have a significant front brake (or has none at all), and has a coaster-brake hub in the rear. if that's true, then if you use a rear hubmotor, you lose all braking ability. there are a number of ways to add a good front brake, and to add rear brakes, depending on fork and frame design, if this is the case. but it complicates your build and increases cost.

You can have a bike shop widen your frame to 135mm, which is a good option if the frame is made from steel.

Like Amberwolf says, you need to figure out how you’re going to stop the bike, because an electric motor almost always results in higher average speeds. Have a functional brake on both front and rear wheels.

Okay thx guys. I think I’ll just go with a front hub set up for simplicity and costs.

Balmorhea said:

You can have a bike shop widen your frame to 135mm, which is a good option if the frame is made from steel.

Like Amberwolf says, you need to figure out how you’re going to stop the bike, because an electric motor almost always results in higher average speeds. Have a functional brake on both front and rear wheels.

Click to expand...

I would just spread the rear to fit from 110 to 135mm.
https://sheldonbrown.com/frame-spacing.html

"I would just spread the rear to fit from 110 to 135mm."

Same here. Make sure it's a steel frame though. Nearly all of the beach cruisers are. While front wheel drive is easier to initially put your eBike together, I think rear drive is safer when you hit the throttle in a curve. Especially if this is your first eBike. Make sure you have a way to have better brakes too.