Billed as the perfect brake for XC or all mountain/enduro use, Formula’s RX has long been a solid aftermarket choice and great OEM score. For 2012, the Italian-made brake gets a new flip-flop master cylinder and the core brake comes in at 242g (plus ~100g for a rotor)- not at all bad for $185. Formula’s a la carte pricing makes pad contact adjustability, tool-free lever position, and all-steel or dual-material rotors optional, allowing riders to buy as much–or as little–fiddleability as they would like. After a couple of months on my go-to trail bike and an Alpine rental, how have Formula’s value brakes fared? Hit the jump to find out!
With a couple of years on the first-generation RXs, I’ve been more than pleased with their performance. On XC and trail brakes, with 180mm on down to 140mm rotors, the previous generation have been workhorses. 
They’ve only required bleeding about once per year- far less often than some brakes and about on par with the best. The second generation maintains the first’s firm but controllable lever feel with plenty of modulation and the ability to really work the edge of traction. They don’t have the gobsmacking power of Shimano’s XTR Trail brakes (which weigh within 5g of the Formulas but cost considerably more) but come out a bit ahead of Magura’s MT6s.
Our test samples came pre-bled and fitted with Formula’s Feeling Control System (FCS) adjuster, which allows for easy free-throw adjustment. Though it adds only a few grams, I’m not someone who ever really wants more free throw at the lever, preferring instead to keep the levers comfortably close to the bar and engaging when the flat of the blade is parallel with the grip. During my stay with FlowMTB in June, my rental came sporting FCS-free RXs- and I never once missed the $45 upgrade. Similarly, I’ve never been overly burdened by having to reach into my pack for an Allen key to adjust lever position, so foregoing other brands’ tool-free lever reach adjustment was never missed.
For our review, Formula provided their 180mm and 160mm (95g actual) dual-material rotors. 
Not only do they save 20g apiece over the company’s steel rotors, but the aluminum carrier is said to improve heat dissipation and reduce noise. In my experience, dual-material rotors are seem less prone to warping from uneven bolt torque. Though they certainly are less squeal-prone than the older steel rotors I have also been running, the fact that the $40/$50 (160mm/180mm) steel rotors are so good and so light make the extra $50 per wheel a tough sell for anyone but the heaviest riders, those who routinely see long descents requiring lots of braking, or those who just can’t stomach a bit of squealing from time to time.
Formula’s choice of steel Allen hardware for lever and caliper mounting is welcome after spending time with (and stripping) lighter brakes’ aluminum nuts and bolts. The RX’s 22mm composite pistons are the same size as those used in Formula’s R1 superbrake, with which the RXs can share pads (with steel backing plates here, as opposed to aluminum). 
In fact, it’s the R1’s aluminum-backed pads save a decent 15g per wheel: racers on a budget would do well to pick up a pair of RXs and upgrade to the lighter R1 pads once the stockers are spent.
In short, the basic RX comes with everything it needs and nothing it doesn’t. My experience with the original RXs has been excellent, and after a long-ish break in period, the new model suggests more of the same. Take it easy on the options and the price is more than competitive. The ability to purchase the lever and caliper assembly separately also makes the Formulas an ideal upgrade for tired, heavy, or high-maintenance brakes while keeping stocking easy for shops. Only a season’s riding will tell for sure, but the RXs are looking like the mid-priced brake to beat- and can even go toe-to-toe with pricier options.
marc
