World Cup mechanic Brad Copeland says this is one of the most overlooked steps when setting up a bike. And Brake Ace’s Matt Miller says the holy grail of good brakes is to bedding them properly. While disc brake pad bedding or polishing is generally only mentioned in passing, it is clearly very important and can have a major impact on your braking performance. Luckily, the process isn’t complicated and is generally* the same no matter what brakes or pads you use.
I’ve collected brake embedding guides from six of the top mountain bike brake manufacturers and combined them with tips from various videos and interviews posted on Singletrack and elsewhere to explain the process and share some of the top tips. Note: I will use the terms embed, polish, and shrink interchangeably below.
The break-in process of the brake
At a high level, bedding in a new set of brake pads is all about transferring material evenly from the pad to the rotor. As Copeland explained to us: “Some of the brake pad material embeds itself into the rotor surface and this gives the brakes more bite once the process is complete; An initial cycle of gradual, medium-effort stops heats the brakes and begins the process of material replacement that coats the new brake rotor surface.” In this Park Tool video, Calvin Jones summarizes that the process “uses heat from the friction of our braking to transfer some of the heat [brake pad] Material to fill the pores of the rotor and remove imperfections.”
All six top brake brands essentially recommend the same basic steps*.
- Accelerate the bike to a moderate speed. Hayes says it’s 15 mph, Magura says it’s 30 km/h (about 19 mph), and the others just say moderate speed. In the Park Tool video, Jones and Truman Purdy mention that they like to roll down a moderate descent, but also that a flat surface works. Most brands recommend riding on a smooth, level surface, and Miller agrees that pavement is ideal. Shimano advises that the area should be clear of obstacles, meaning one section of the trail is less than ideal. This is a time when you want to ride your MTB on the pavement.
- Once you’re riding at a moderate speed, use the brake to slow the bike down to walking speed (about 2.5-4 miles per hour), one wheel at a time. The idea is to brake hard but not lock the wheel and avoid a complete stop. Note that Magura has a very different recommendation for this step, so be sure to read the brand-specific notes below.
- Repeat steps 1 and 2 about 20-50 times for each wheel. Again, each brand has slightly different recommendations, so read on.
Shimano’s instructions are among the most straightforward and straightforward, advising that riders should “apply your brake lever with moderation, especially when using the front brake”. This appears to be more of a safety recommendation than anything to avoid endo during the procedure.
I have been riding SRAM brakes for many years and after researching brake polishing I have to say that the adjectives they use are somewhat at odds with the other brands and even the experts. As a result, I’ve probably been doing it wrong for a while. Like Shimano, SRAM adds a small safety CYA for the rider, beginning their instructions with the words, “The bed-in process requires you to perform difficult braking” which could lead to an accident (emphasis mine). In the past, despite the following instructions to avoid locking the wheels, I probably meddled with the hard braking part more than I should have. SRAM instructs riders to do this Celebration In step 2, brake and repeat 20 times at a moderate speed. Again, I and other riders may have latched on to the word more firmly than we should have.
Coincidentally, SRAM recently released a video that included helpful information on the bed-in process. I have reached out to SRAM to clarify the wording the brand is using in their manuals versus the video but have not received a response as of press time.
In addition to the basic steps above, SRAM recommends increasing the speed from moderate to a “faster speed” and repeating the braking process 10 more times, for a total of 30 times per brake.
Unlike the other brands I’ve looked at, Magura recommends bringing the bike to one complete stop in step 2 of the polishing process. They also recommend a higher speed – 30km/h – than the other brands and say to repeat the process at least 30 times.
The TRP instructions are almost identical to those of SRAM. The brand recommends 15-20 slows at moderate speed, followed by 10-15 slows at higher speed.
Hayes recommends following the basic procedure outlined above and repeating it 50 times. So plan well in advance of your first ride with a new set of Hayes brakes or pads. The brand also says to keep your speed at 15 mph or less throughout the break-in process.
Hoping for recommendations
Hope makes no specific recommendations as to the speed you should wear or the number of times the bed-in procedure should be performed. Like the others, they recommend slowing but not stopping the bike, saying the brakes reach their full potential after breaking in and then after the first few rides.
Added braking breaks in tips and tweaks
Copeland says, “I like to pull back up to speed with a little drag to keep them hot.” In their video, Jones and Purdy have a different take and suggest riding with the brakes wide open between squeezes to allow the rotors to cool . Not only that, but they alternatively suggest spraying the pads with water between steps to create a slurry with the pad material. While this may sound unconventional, I found a reference to a similar process in a Hope owner’s manual from a few years ago, which said it “helps to pour clean water over the caliper and pads when bedding”.
According to Magura, larger rotors require more break-in time, and lighter riders may not be able to bed properly in brake pads paired with large rotors.
As always, avoid touching the braking surface of the brake pad or brake discs to avoid contamination before or after embedding, which can significantly affect performance.
frequently asked Questions
Why do brakes need to be broken and broken in?
Magura explains it best: “During the running-in phase, the smallest bumps are ironed out in order to create the optimal friction surface between pads and brake discs. In addition, embedding your pads removes any residue from the manufacturing process from the brake pads. Optimum performance and durability are only achieved once the break-in period is complete and both the pad and rotor surfaces are fully matched.”
Does braking in make a big difference?
While brake bedding procedures may differ slightly, all brands agree that this is an important part of maximizing braking performance. Hayes says, “Braking hard before proper polishing can result in a reduction in braking performance.” TRP notes, “Bedding in your new pads and rotors is critical to brake performance. Proper bedding of your pads and rotors will ensure the highest performance and the best operating conditions.”
How many times should I repeat the process?
As mentioned above, each brake manufacturer has a slightly different recommendation, although on average most would agree that it takes around 30 cycles to properly polish a brake.
Why shouldn’t I come to a complete stop when breaking in disc brakes?
Regardless of Magura, TRP states that a full stop “can result in uneven pad material deposition and affect the performance of the brakes while riding.” In the Park Tool video linked above, you can even see how the brake material accumulates unevenly during hard stops.
How do I embed rim brakes?
Good question! This article focuses specifically on disc brakes and the procedure for rim brakes is not the same. Rim brakes are more complicated due to differences in rim braking surfaces, materials, and shapes.
*See brand-specific notes and tweaks listed under basic instructions.