First Impressions: Magura MT8 Carbon Disc Brakes
Magura’s new MT8 disc brakes claim to have the world’s first carbon fiber master cylinder. Combined with their carbon/thermoplastic resin lever blades easily put them under 200g per wheel (excluding rotor). I’ve had my set installed on my Niner Jet 9 with a 160 front/140 rear rotor for a bit now and have been testing them in basic XC settings. No major downhills yet, but enough to get a good first impression for you.
But first, let’s see what’s in the box and how much everything really weighs, shall we?
From left to right: 140mm (73g), 160mm (96g) and 180mm (118g) rotors.
The set of brakes we received for testing had been ridden previously and had a small superficial nick in the rear hose. I’ve covered it with a bandage and it hasn’t been an issue, but I’m keeping my eye on it. In terms of weight, the hoses were cut to 61″ for the rear (191g) and 29.75″ for the front (175g). How much this differs from production sets I don’t know, but likely not much since my bike is on the larger side of things these are likely to go on.
The weight savings on these comes in large part from the use of directionally oriented carbon fibers in the master cylinder body. Magura says they’re laid up to counter stresses typically put on that piece. The lever blade is a mix of short- and medium fibers in a thermoplastic resin. Whatever it is, it’s light. I dropped several ounces over the XX brakes I had on my bike.
About that lever assembly: The body holds fixed threaded male screws with female bolts that fit through the carbon fiber clamp top to secure it to the handlebar. It’s a bit different than other brakes we’ve tested. Because it’s not Matchmaker compatible (or with Shimano’s system for that matter), it means you’ll have more stuff clamped to your handlebar. Unlike the Ashima PCB’s, though, they didn’t require any weird compromises to get the shifters and levers both in their happy place.
The rotor bolts are aluminum and weigh just 5g. Against my weight weenie tendencies, this is one area where a couple more grams for stronger bolts would be welcome. I’m pretty sure I broke one while gingerly installing the front rotor. I left it be for now because I’m in denial, but it’ll get a once-over here shortly and I’ll probably swap bolts for some titanium or stainless steel ones.
Combined, the 160mm rotor, bolts and front brakes come in at 276g, which is 2g under claimed weight, but keep in mind our hose was trimmed some. In our experience, though, the hose and enclosed mineral oil don’t weigh much…just look at the difference between front and rear weights, noting that the rear hose here is more than double the length of the front.
HOW DO THEY PERFORM?
After a short break in period (the rotors were new), they’re working really, really well. There was a bit of chatter from the rear for the first couple miles, but it’s been gone since. The front makes a bit of a squeal when pulled beyond half way. However, that’s surprisingly infrequent during my normal XC riding. The brakes are mounted to a Niner Jet 9 using an Avid rear brake adapter (Magura didn’t send a 140 adapter). Up front, they’re bolted directly to a Rockshox SID 29er.
Some longer, sustained downhill action is in the plans for the next couple months after Eurobike and Interbike let me get home, but so far the braking performance is impressive. Considering I’m currently about 190lbs fully dressed with Camelbak, 6’2″ tall and riding a large 29er, the fact that a 160/140 rotor combo works perfectly for my local XC trails is solid. It lets me keep my weight weenie tendencies intact without sacrificing performance.
Having been almost exclusively on SRAM/Avid and, to a lesser extent, XTR brakes for the past year, I had shifted to using my pointer finger to brake. Prior to that, I was a middle finger braker for as long as I can remember. Using these brakes was, uh, like riding a bike. I’m right back to middle finger braking and it feels perfectly natural. Because of the lever shape, it just seems to provide better leverage and control.
The Magura MT8s move the pads into contact rather quickly, but not too forcefully. Under normal xc riding/racing conditions, I’ve rarely had to apply more than half a lever pull to slow enough to negotiate my local trails. Granted, I know where I’m going pretty well on these, but there are still some emergency stops here and there that prove the brakes have plenty in reserve when necessary. Just based on initial impressions, I have to say I like these brakes quite a bit, I’m just hoping the front brake squeal under hard braking will go away on its own.
I plan on swapping to a 160mm rotor in the rear halfway through some mountain descent testing in Asheville and VA this fall before compiling a final report. Stay tuned.