Words by: Liam Woods
Shimano XT brakes VS SRAM RSC brakes. Is there a winner? Which is better? Opinion or fact? These are what could be considered the biggest rivals in the MTB world right now. Many people stay true to the brand they have been riding and many others just ride it because it is what it is. For a handful of people, brakes are very important and knowing the exact differences between rivals like SRAM and Shimano is essential for them to stay alive. Because of this, we dissected the two to make it easy for you. Now, let's break apart these two disc brakes and see what each have to offer!
Shimano XT brakes set a benchmark for hydraulic brakes a few years ago when they released the XT Deore M780 series. A reliable brake with tons of power, many bikes from high end to low end started to rock the Shimano XT brakes. Many OEM bikes started coming with SRAM drivetrains and Shimano brakes. Avid brakes, at the time, had some reliability issues, so Shimano XT remained the ticket. Fast forward a couple of years and the Avid name has been tossed out the window and SRAM stepped up their braking game with a 100% redesigned lever and caliper. Probably the only thing to stay the same is the use of DOT fluid and their Matchmaker clamp system. Can SRAM make a brake that competes with what is arguably the most reliable disc brake on the market?
SRAM Guide RSC brakes are about the same level in their line up as Shimano’s XTs. Both sets are one level from the highest end, but are still affordable to some extent, so let's break into these brakes.
SRAM brakes use DOT 5.1 fluid while Shimano uses mineral oil. There is a lot to argue which one is better. In my eyes they both can be bled easily, they can both be difficult to handle, and neither can be mixed. Also, I wouldn't get either on my skin if I could avoid it. Both brake sets have a tool-free lever adjustment, which is an easy-to-turn knob on the front of the lever. They’re both nice, quick adjustments. SRAM has a pad contact adjustment on the RSC, while Shimano has what they call “free stroke”. Honestly, I don't think the “free stroke” adjustment does much to anything on the XTs. The contact adjustment on SRAM is very defined and really easy to feel the difference. When comparing the two in this department, the SRAM comes out as the clear winner. Down at the caliper things get a bit different…Shimano XT has a two piston design (4 piston coming soon, but not yet available) that uses ceramic pistons.
In addition to the ceramic pistons, which aid in cooling/overheating, they come with finned brake pads designed to grab some passing air and shoot it down into the pads and rotor below. While we have not done any testing with finned and non-finned pads, Shimano claims there is a significant improvement with air flow. SRAM took a slightly different approach with the RSC caliper. The pistons are a bit smaller than their Shimano counterpart, but while the pistons are a bit reduced in size, you get two more for a total of 4 (more is betterer, right?). Additionally, SRAM redesigned the bleed port on the caliper which they dubbed “Bleeding Edge technology”. This redesign makes it significantly easier to hook up a bleeding syringe. Using a 3mm allen, you can attach the bleeding edge tip to the bleed port and back it out ¼ - ¾ turn and start bleeding. When done, tighten it up without any loss of fluid and the system becomes closed with no chance of air getting in. It’s a major improvement to their old system, resulting in a very clean bleed with no mess to clean up at the caliper side.
When comparing installation and ease of bleeding between SRAM and Shimano, I would say Shimano still takes the crown. With Shimano, a simple cup at the lever and pushing some fluid from the caliper up to the lever is half the process. Then a simple cycling of the brake lever to push the air out. SRAM's process is a bit longer and more involved. Hook up two syringes and follow a cycle of suction, push, clamp, etc. There are many more steps and you're actually trying to get the air out by force. Still, once you know the cycle of this bleed, it becomes simpler and by using vacuum suction to your advantage you can get a really airtight bleed.
Immediately you can notice a pretty major difference in lever feel between the two. Shimano XT brakes have a much more powerful “bite”. Shimano employs their Servo Wave action, which is a technology that gives the initial stroke of the lever some resistance and the end a very positive, firm stop. Some say it decreases modulation while others say it helps get a better bite. Either way, it’s there and it’s noticeable. SRAM has a much smoother lever feel and when the bleed is good there is still a positive end stroke to the pull. I think the SRAM has better modulation and you can really tell when pulling the brakes side by side without even needing to ride.
Of course, with any comparison, the real test doesn’t start until you get on the trail. If you’re jumping between the two, your braking might be all over the place. You might find yourself grabbing too much brake on the XT vs. not braking soon enough with the RSC. However, it really only takes a few minutes to get used to either one. Since I am not a heavy rider, I do like to brake late into corners and also scrub speed vs. braking hard to coming to a stop. Pulling manuals is easier to begin with on the RSC brakes as they do not have as hard of a bite as the XTs. While the hard bite of the XTs might feel like they are more powerful to begin with, once both brakes are pulled in hard and you are looking to stop fast, I feel they both have equivalent power. Under the same conditions I think both brakes can be good for riders of all sizes. I will say that I often found myself grabbing a little too much lever and ended up locking up the XT brakes when I didn’t mean to. That being said, I found the XTs maintain a more consistent lever feel when on a long extended downhill. While the RSCs were good, they experienced a little fading. A few pumps of the lever here and there remedies the situation quickly. While both of these brakes firmly belong in the trail bike lineup, trail bikes are oh so capable and I find myself sending it down what was previously a DH-only trail on 120-140mm bikes. It’s in these scenarios that you can really push some brakes to the point of failure. Both the RSC and XT brakes held up, kept me on the trail and going as fast as I can, and after all, brakes only slow you down, right?
While Shimano XTs have been the go to for a couple years now, I wouldn't count out the new SRAM RSC brakes. With many more people running SRAM Eagle now, the Matchmaker system provides a clean way to get both drivetrain and brakes on a single clamp, making things easy on the eyes. In the end, however, riding style plays into your decision. If you’re looking to stop on a dime and brake late, the Shimano XT might be the ticket fo you. Looking to scrub speed and hold manuals like a #manualmonday champ? Try out the RSC brakes. While there is no definite winner in my eyes, if you can ride faster and have more fun with one of these options, I think that’s the winner right there :)
This article was written / authored by Liam Woods. Liam has been in the bicycle industry for over 10 years as a racer, professional mechanic, service manager and as of late, media and content creator. Liam has ridden thousands of different bikes, ridden countless components, tested endless MTB apparel of all kinds and written reviews on it all. He's a key piece to the Worldwide Cyclery "All Things MTB" content creation puzzle. He also makes consistent appearances on the Worldwide Cyclery YouTube channel and Instagram.