WHAT: Magura Marta SL disc brakes
HOW MUCH: $300 per wheel
At 324 grams per wheel (that's the whole shebang…brake levers, rotor and caliper) the Marta SLs are the lightest hydraulic disc brakes available and are aimed directly at the "I won't buy it if it isn't made out of carbon and weighs more than a speck of fly poo" crowd. Magura kept the weight down by spec'ing the unit with a carbon fiber brake lever and a lightweight caliper machined from a single piece of aluminum. Other nifty features include self-adjusting pads, reach-adjustable brake levers and a six-inch wavy rotor that Magura claims helps the system shed mud.
The Marta SL is a twin-piston, open hydraulic system that (like Shimano's systems) relies on mineral oil rather than DOT fluid. The upside of mineral oil is that it doesn't absorb water over time and it won't blister your paint or irritate your skin when you spill it all over the place during brake bleeds. The downside of mineral oil is that it heats up more easily during long descents than DOT fluid. Mineral oil is also more sensitive to outside temperatures (particularly cold weather) than DOT. Such scenarios can lead to an inconsistent feel at the brake lever.
The first thing I noticed about the Marta's was the excellent feel at the brake lever. The lever is beautifully sculpted…It just mates perfectly with your index and middle finger….sorta reminiscent of old school XTR lever blades….ooooh-ahhhhh.
The Marta's also offer a ton of modulation. If you're not a fan of the very deliberate "On—Off" feel of disc brakes like Hayes, you'll love the Martas. Regulating just the right amount of stopping power and avoiding the dreaded rear wheel skid is stupid-simple with these brakes.
Despite these two excellent traits, I was sort of leery about the Martas for the first six months or so of riding. In the past, I'd had great luck with Magura's Louise and Julie disc brakes, only to have both models repeatedly crap out on me in the middle of long rides. There's nothing worse than riding hours of steep, east coast slop with only your front brake functioning.
I was mightily relieved to have encountered no such problems with the Marta SLs. I've spent a solid year riding these things on both mellow XC trail rides and some loooong Sierra Nevada downhills with no leaks and just the occasional trace of brake fade. Magura, for their part, is so confident in their latest generation of brakes that they offer a five-year no-leak warranty on all their models. Sounds like a good deal to me.
Things I wasn't so keen on? For starters, while I loved the brake lever's shape, I'd personally probably opt for an aluminum lever blade. I crash a lot (you can read whatever you want into that statement) and would hate to cough up the cash for a replacement carbon lever. Brake set-up was also a bit of a drag. Setting up the Maguras is no more difficult than dialing in a pair of Shimano or Hayes brakes (which also require futzing about forever with shims to kill rotor rub), but at this premium price point, I'd like to see every disc brake manufacturer design an adjustment system as intuitive and simple as Avid's. How can I get this sucker to stop dragging? Two shims on the front bolt and three on the back? Three shims on the front bolt and four on the back? There's gotta be a better way.
I'd also like to see Magura offer the Marta SL brake levers with a split perch (a la Hayes and Avid) so that you could easily swap brake levers from onr side of your bars to the other without having to disconnect the brake lines—a very handy feature for those times when you are swapping bikes back and forth with someone who rides their brakes moto-style (right brake lever controlling the front caliper instead of the rear unit). It's a minor thing, but if you're going to pay this much for a set of brakes, shouldn’t the levers be ambidextrous?
But, hey, I'm nitpicking. When it's all said and done, I like the Marta SLs. Freeriders will obviously want something with a larger rotor and more stopping power, but for general cross-country riding, these brakes offer excellent performance. Not as much raw stopping power as Hayes' HMX-9 Carbon brakes, but on a par with Avid's Juicy 7s and Shimano's XTR models. Modulation, again, is top notch which makes the Marta SLs an excellent choice for anyone transitioning from side-pull brakes to discs.