RR 511 As versatile as it is robust ? a rim for every surface! Anyone who wants to build a super-stiff and reliable wheel is in the right place with the RR 511. Thanks to the latest aluminum alloy and surface treatment, this 32 mm high semi-aero rim is lighter than you might think despite its robustness. And if you're thinking of using it on unpaved roads or the cross course, simply mount tubeless tires in the rim bed provided for this purpose