RR 521 Unexpected rough stretch on your route? No problem with this rim! Are you looking for bombproof rims for your gravel or cyclocross bike? Our new RR 521 rim has plenty going for it. With a depth of 32 mm and a width of 20 mm, it would certainly have landed in the cross-country category a few years ago. But today, this model is a fantastic opportunity to widen the playground of your road bike.