20 inch rim recommendation?

[dozentrio]

Hi folks,

I recently took my folding bike belt drive for a 120 km trip and close to the end my rear rim sidewall failed. I suspect it was due to running 90 psi on rims that weren't intended for that. I want to replace the rim with something more durable but I'm a bit lost as to what rim to chose. Unfortunately due to using a nexus hub, I can't easily switch to disc brakes so I need rims with a rim brake track.

My local bike shops are either too busy or unwilling to help, and tell me that their suppliers can't send them rims any time soon.

I've checked ebikes.ca and they have a number of 32 spoke wheels, but I don't know which one is best suited for my bike (if any). The original rims are 25 mm diameter for the brake calipers... I don't imagine I can go too much wider than that.

Does anyone knowledgeable about rim selection for the ebike type weight/speed/tire pressure have any recommendations?

 

[Balmorhea]

Sun Rhyno Lite is a good strong proven rim in that size category. It's about 27.5mm wide (but there's an XL version that's wider). If you use one of those, a replacement rim will be easy to find going forward.

If you can find a specimen of the out-of-production Alex DM24 in 20" size, that's stronger enough to be worth dealing with its 31ish mm width.

Nexus gearhubs support Shimano Roller Brakes, which don't require any brake mounts. Some of them are lame, but BR-IM70 and higher numbered versions are pretty potent, especially in a 20 inch wheel.

There probably a big plastic dustcap-looking shroud on the left side of your hub. Underneath it will be a spline for mounting a Roller Brake.

P.S. -
90 psi in Maxxis Hookworms will make your bike ride like crap, but it won't buy you any extra speed, tire wear, or rim protection versus say 60-65 psi. Try lower, not low, pressure and see whether it doesn't make your bike ride better.