Originally Posted by
cyccommute
Companies certainly thought they were a mistake. They dropped them like hot potatoes and even went back to cantilevers. Most brake systems can still be found on various quality bikes even now. Center pull calipers (Mafac style) are very rare but Paul still makes a version of them. Cantilevers are still available on a wide range of bikes. Disc brakes have replaced linear brakes but you can still find new bikes with v-brakes. The only place you’ll find u-brakes are on some freestyle BMX bikes. Nobody else wants to touch them.
U-brakes work great. They are, after all, simply beefed up centerpull brakes, a design specced on millions of bikes over the last century. While centerpulls have lost popularity since the early 80s, it's not due to their braking performance but rather due to the ease of setup and marketability of sidepull brakes. In my opinion they are often more rigid than sidepulls and therefore offer slightly better braking performance. As to u-brakes, yes, the under-the-chainstay placement of mountain bike u-brakes in 1986-1988 was not the best idea, but the brakes themselves are great. Cantilever brakes offer more mud clearance and are a bit lighter, but generally do not offer better braking performance than u-brakes. In the vintage mountain bike world, some of the most sought-after bikes from the late 80s and early 90s are those with variations on u-brakes, by that time mostly mounted on the seatstays: Cunningham's lever-link brakes, WTB Speedmaster roller cams, and many other "boutique" brakes that boasted amazing performance compared to cantis, if you were willing to spend some time learning how to set them up. As far as BMX goes, u-brakes are the standard and there is quite a booming industry with hundreds of companies offering their own models.
By the way, centerpulls are still being made by a few more manufacturers than Paul. Rene Herse and Dia Compe both still manufacture them, for example. Dia Compe has at least 4 models under its own branding, plus they manufacture two separate models for a Japanese company called Grand Bois. Not to mention their full line of BMX u-brakes, starting with the cheaper cast Diatech "Magic" brakes up through their famous forged 990 model line from the late 80s, followed by their top-of-the-line "Box" U-brake which is fully CNC-machined.