Rims

We stock a number of 32 and 36 hole rims ranging in size from 16" up to 700c. These are used for doing custom wheel builds, or for those who want to lace up a non-electric hub to match their electric wheel. Most of them have eyeletted holes that will fit regular 14g nipples or 13g reduction nipples (13g ID with a 14g OD). For the larger 13g or 12g nipples, the rim holes would need to be drilled out.

How rim sizes work (why a 20" rim measures 16")

Bicycle rims are named after the tire that goes on them, not after the rim itself, so a bare rim always measures a good deal smaller than its name. A "20 inch" rim is 406mm across the bead seats, which is about 16 inches on a tape measure. That is correct and normal: it is the size every 20 inch tire is built to fit.

The number that actually matters is the ISO bead seat diameter (also called ETRTO). Some tires print it on the sidewall (for example 50-406), but many only show the inch size. A tire marked 20 x 4.00 (406) fits any rim marked 406, and nothing else. Match the ISO number and the tire will fit; match only the inch name and it might not.

Two things that catch people out. First, there are two different rims both called 16 inch: ISO 305 is the kids-bike and trailer size, ISO 349 is the larger Brompton and recumbent size, and they are not interchangeable. Check which one you need before ordering. Second, on fatbike rims the inch name stretches further still, because a 20 x 4.0 fat tire stands a lot taller on the rim than a 20 x 1.75 does. Two wheels both called 20 inch can therefore finish at noticeably different overall heights, so do check clearance in your frame or fork. The 20 is only there to tell you which rims and tires pair up.

Every rim below lists its ISO size, width, spoke holes and ERD under the Specifications tab on its own page, and you can narrow the list by size and spoke count using the filters in the sidebar. Building the wheel yourself? Our spoke calculator has all of these rims in its dropdown and will work out your spoke lengths.