Need New Rim For RadCity

My 2018 RadCity has some hairline cracks in the rear rim which stem from some of the spoke holes (each crack is about 1/2 inch long). I'm told that Rad rims aren't the highest quality, and that getting a heftier replacement rim would be a good idea. Any recommendations for rims? The tire itself is 26 x 2.3. Thanks.

enargins said:

My 2018 RadCity has some hairline cracks in the rear rim which stem from some of the spoke holes (each crack is about 1/2 inch long). I'm told that Rad rims aren't the highest quality, and that getting a heftier replacement rim would be a good idea. Any recommendations for rims? The tire itself is 26 x 2.3. Thanks.

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Cracks around the nipple holes usually indicate spokes were used that are too thick for that rim (probably 12g). This is very common in hubmotor builds, caused by people (individuals and companies) not understanding how wheels work, and using rims not capable of handling the tension required for thicker spokes. It doesn't really have much to do with the quality of the rim, just what it is designed to handle. Even the "powercircle" rims that come on a lot of generic hubmotors aren't bad if used with the thinner spokes they're meant to be used with.


Generally you'll get a better stronger wheel build by using thinner spokes, like 14-15butted, and any decent eyeletted rim. You'll need new spokes anyway, unless you get the exact same rim to replace yours, or one that happens to have the same ERD. Weinmann rims are good, as are a number of other brands. This rim would probably work for you:
https://ebikes.ca/shop/electric-bicycle-parts/rims/rim26-ez.html
Rim Width (mm) 22.5
Spoke Holes 36 Hole
Nominal Rim Size 26" (ISO 559)
Rim ERD 543
Rim Brake Compatible Yes
Valve Type Schrader
and then you could order these spokes if you want thicker ones than the usual
https://ebikes.ca/shop/electric-bicycle-parts/spokes/spcust14.html
in the right length which you can determine from the calculator here:
https://ebikes.ca/tools/spoke-calc.html
which has info to tell you how to measure the things needed to get the right spoke lengths with it. If it's a rear wheel, keep in mind the drive side spokes are usually shorter than the left side, to ensure the wheel is centered while leaving space for the sprocket cluster on the right.

If you want to use the 14-15 butted then Danscomp makes whatever you need, though you will probably have to call them rather than ordering from their site. (you do need to use the above info to find the right length first, though).

Thanks for the info! Appreciate it!

I am told that overtightening the spokes causes cracks in the rim. And, indeed, that's what I did. I had some loose spokes, and one broke. So when I replaced the spoke, I seriously overtightened the spokes (like an idiot) so that they wouldn't come loose again. I'm pretty sure that's what's caused the cracks in the rim.

I'm on the Rad Facebook group all the time, and there are like 40,000 members there. I don't recall hearing much about cracks in the rim, though people do complain of other problems from time to time. So I don't think it's a problem with the type of spokes Rad uses. I believe it's just user error.

As for spokes being shorter on the drive side, that's interesting. When I ordered my replacement spoke from Rad, they asked if it was front or rear wheel, but not which side it was. This tells me that their rear wheel spokes are all the same length. So that's interesting about having two different sizes on the rear wheel.