Magura MT8 carbon fiber mountain bike disc brakes review

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?

Magura MT8 disc brake rotor weights for 180 160 and 140mm mountain bike rotors

From left to right: 140mm (73g), 160mm (96g) and 180mm (118g) rotors.

magura mtb carbotecture carbolay carbon fiber master cylinder on a mountain bike disc brake

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.

magura MT8 carbon fiber disc brakes review with real weights for rotors caliper and lever

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.


Magura MT8 carbon fiber mountain bike disc brakes review Magura MT8 carbon fiber mountain bike disc brakes review

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.

Magura MT8 carbon fiber mountain bike disc brakes review

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.


  1. Maple Leafs on

    Strange, I have no squealing noise from my MT8. Super quiet with great braking power (comparable to shimano’s, but much lighter feel) and great modulation (comparable to their Marta SL). They are much better than XX; XX has some major squealing issue (turkey gobbler, as frequently mentioned by other users).
    Only downside is that MT8 are pricey (slightly more expensive than XX), but I would buy the MT8 over XX in a heartbeat.

  2. alloycowboy on

    Carbon Rotors are a no go on a mountain bike as they do not generate enough heat to become effective. Check out Scrubb Components to see the next best thing which is Metal Matrix Composite Rotors.

  3. Maple Leafs on

    A Scrub Racehorse rotor costs $215 each (from their website), not including rotors or brake pads (with those costing $245/rotor). Also, these rotors are thicker, so one needs more care in centering brake calipers. As for braking, I notice little difference with the regular rotors with the Scrub rotors. You can easily knock off 100-150 grams off your bike. However, I don’t think Scrub makes brake pads compatible with the MT8 brakes yet, and I don’t think MT8 brake pads that comes with the brakes are organic (requirement for Scrub rotor use).

  4. deanopatoni on

    Thanks for the review Tyler.
    Once you get some downhill ride time it would be really interesting to get your impression of these brakes in comparison with XTR trail brakes, i.e. which would you choose??

  5. someslowguy on

    tyler – i’m looking forward to seeing these things!!! p.s. i’ve been satisfied with 3 Ti bolts per wheel. its worked fine all year with 160/180. rad!

  6. Bluur on

    @someslowguy 3 bolts, and Ti at that? Jesus dude. 3 bolts gives you an even stress pattern at least, but it gives you zero redundancy – one bolt loosens up or lets go and you’ve got a critical system failure that will almost certainly lead to a crash, possibly at high speed.

    At the very least put alloy bolts for the other three – it will add about 2.5g on each side. If you can’t deal with adding 5g to your bike for safety, you should ride without a helmet, gloves, or shorts – so much weight savings!!!

  7. bk on

    @someslowguy: saving 6 to 8 grams by only using 3 rotor bolts? For shame….you’re seriously asking for trouble with this and when it happens out on the trail you’ll be seriously bummed.
    Why would Magura include aluminum rotor bolts? I love my old Marta SL but any aluminum bolts for me would be for bottle mounts only.

    As for this MT8 brake, is it designed for XC or Trailbike use? I’m happy to see my investment in carbon bladed Formula R1 set is still going strong after just a bit over 1600 singletrack miles and about 55 grams lighter overall using ti bolts (rotor/post) and a 160/180 setup on size large epic.

    Peace to all and many, many happy miles…

  8. Jdog on

    I have about a month of riding on these. The only neg I can give is the alloy rotor bolts. Too light. Period.

    The lever feel is amazing. These have been quiet as can be. Super braking and good modulation. Happy times!!

    Although I have the Mt8, I would tell anyone to go for the Mt6.

  9. Rogue on

    Why is everyone so worried about any thing less than a 100gr. This will not make you faster. you on a Mt Bike, take a big piss before you ride and that will save more and remove it from the most critical part.

  10. someslowguy on

    attn blur, bk and rogue – i appreciate your concern for my safety or lack thereof. i mainly set things up this way (after some slower, easier rides to be sure it held) because i was installing rotors on four wheels and swapping front axles between 9mmQR and 20mm thru-axle and simply was interesting in saving time – i’m a fat slow guy so the weight doesn’t bother me. i have my carbon hardtail setup with ti bolts and my 5.5″ 29er full suspension setup with steel bolts (also three front/rear). this setup has worked now for nearly a year of racing and even riding super techy gnar-er trails than you guys have ever seen.

    just kidding, actually the important part for me is, unlike you guys who actually ride bikes i just drive around charlotte, nc with my expensive lightweight bikes on the back of my rangerover to look cool. when you are driving like me around you don’t need the helmet, gloves or shorts. just saying.

    as for the magura brakes, usually i dismiss magura because they’re well, maguras – BUT – these are the first magura’s that have made me look twice. i’m sure they’ll look killer on my bikes, and even for riding on the trails.


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