Horror news scared mountain bikers at the end of the year: front wheel tubes suddenly bursting, brakes failing on fast downhills, knife-sharp rim parts endangering the rider's life and lots of dramatic crashes. If you believed the press reports, breaking rims were an imminent danger to every biker - and mountain bikes were especially dangerous. Also the alleged reasons seem easily made out. Shimano’s high-performance V-brakes and Magura’s Hydro brakes were revealed exemplarily as rim destroyers in the first instance. Finally, rim brakes in general were called into question as faulty designs. These sensational reports united with the borders between facts and speculations becoming less clear. Our investigations show, what the subject of rim failure really is all about.
First of all: It is not new that braking can harm and even destroy the rim. Bikers who ride a lot have known this phenomenon since aluminium rims were introduced for bike wheels in order to safe weight. In comparison with conventional steel rims, the surface of aluminium rims is softer - and increasingly exposed to the aggressive power of the new brakes. Nevertheless, breaking rim sides cannot simply be blamed on V-brakes or other models. The rim's wear depends on the way you brake.
Author: Dirk Zedler