It's no secret that Formula make most of our favorite disc brakes. A history of packing excellent modulation, great durability, and reasonably to freakishly light weights has put the Italian company's offerings at the top of the bikefix shopping list. This January, looking to replace the Avid Elixir CRs that came on a new bike, I decided to put my money on Formula's new entry-level RX discs.
At about $145 per wheel, plus $30-50 for rotors and adapters, the RX aren't cheap brakes. They are solidly mid-priced, though, and made in Italy- and half the price of the company's lightweight R1 or downhill The ONE. Given my 3 years' experience on one set of Oro Biancos, which have only just needed bleeding, the RX seemed like a safe choice. At a claimed 351g for a front brake with 160mm rotor, the RX are also a solid 25-40g lighter per wheel than the Elixir CR's they replaced.
For my 6in trail bike, I chose to pair the RX's with a 180mm front and 160mm rear rotor (both Shimano centerlock, which I already had). The brakes installed easily and I was able to trim the hoses (using the included spare fittings) without needing to re-bleed the brakes. While the lever pivots did have a bit more play than I would prefer, everything else seemed promising. I bedded the steel-backed organic pads in with a few hard stops and hit the trail.
While the RX's levers are a bit broader than I tend to prefer (Shimano levers are my favorites, with the Oro Biancos a close second), that's quickly forgotten when it comes time to stop. Even new, the RXs are some seriously powerful brakes. While my light weight shouldn't challenge any modern disc brake, the RXs are noticeably more powerful than the Formula Oro and Shimano XTR discs on my other bikes. So much so that it takes a bit of technique adjustment to keep them from locking up on loose trails. The RXs also have considerably less free lever travel (before the pads make contact with the rotors) than anything else I can remember riding. As a result, it's possible to set the levers up fairly close to the bar and comfortably cover the brakes with the middle finger without the lever ever bottoming on the bar (or other fingers). The short throw is by far the thing that I miss most when returning to my old brakes.
Over the past several months, I've been spoiled by the RXs' performance. They don't have some of the frou-frou pad contact or leverage adjustments that some higher end brakes boast- but I haven't missed them one bit. I liked the first set so much that I bought a second for my cross country bike (and am now considering a third for another bike). My only complaint so far has been that, when used with my (used) Shimano XT and XTR centerlock rotors, a bit of coarseness can be felt through the levers and even the pedals when braking. That does seem to be a rotor issue, though- of the four brakes, the brake run with a Formula rotor is the quietest and smoothest.
For the money, I'm not sure what else compares. The RX are some darn lightweight, powerful brakes. So powerful, in fact, that for the first time ever, I'm considering a 160mm front/140mm rear setup on my cross country bike, if only to keep them from overwhelming the XC tires' grip. More after a summer's big rides and long descents...
Chris from Formula's US distributor has been in touch to let us know that Formula do not recommend running their brakes with other companies' rotors. This is especially true of Shimano rotors as they have a relatively narrow brake track. This could explain some of the noise I've been experiencing... Until the company's own Centerlock rotor is released, Formula do make a $45 Centerlock adaptor allow their discs to be used with Centerlock hubs.