Which Disc Brake Pads Fit My Bike? A Plain-English Guide
Working out which brake pads your bike takes is more confusing than it has any right to be. Shimano alone has used dozens of pad shapes across the years, the code stamped on the pad isn't printed anywhere on the brake, and the model number on your calliper is usually hidden behind the wheel and covered in road grime.
This guide walks you through identifying what you've got, choosing the right compound, and knowing when to replace them. If you'd rather skip to the answer, the fitment tables are further down.
Start with the calliper, not the bike
The single most common mistake is looking up pads by bike model. Manufacturers change brake specifications mid-year, swap components based on what's available, and sell the same frame with three different brake sets across a range. Your bike being a 2022 model tells you very little.
What you need is the number printed on the calliper — the part that clamps the rotor, down by the wheel.
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Where to look: most Shimano callipers carry the model on the outward-facing side of the body, usually in small text near the hose fitting. Something like BR-M8120 or BR-MT200. The BR prefix simply means brake. Hope callipers have the model cast or printed into the body, though you may need to clean it to read it.
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If you can't read it, count the pistons instead. Look into the calliper from above with the wheel removed and you'll see either two pads pushed by one piston each, or larger pads pushed by two pistons each side. Two-piston and four-piston brakes take completely different pad shapes, and this alone narrows things down enormously.
The failsafe: take the old pad out and compare its shape against product photos. Pads are held in by a split pin or a threaded bolt through the top of the calliper. Once you've seen the shape, matching it is straightforward.
Shimano fitment
Shimano's two-piston brakes fall into three broad eras, each with its own pad shape.
| Your brake | Pad you need |
|---|---|
| BR-MT200, MT300, MT400, M445, M446, M485, M486, M515, M525, M575 | B01S-fit semi-metallic pads |
| BR-M975, M966, M965, M800, M776, M775, M765, M665, M601, M596, M595, M585, M545, M535, R505, T665, T605 | Older XT, SLX and Deore pads |
| BR-M785 (XT), BR-M666 (SLX), BR-M985 (XTR 2011) | 2011–2015 generation pads |
The B01S shape in the first row is the most common disc pad in Britain. If your bike came with hydraulic discs and you've never changed the brakes, there's a good chance this is what you need.
Four-piston Shimano
| Your brake | Pad you need |
|---|---|
| BR-M8120, M8020 (XT), M7120 (SLX), M6120 (Deore), MT520, MT420, M820/M810 (Saint), M640 (Zee) | Four-piston pads, semi-metallic or carbon |
These pads are visibly larger than the two-piston versions. If you're unsure which you have, the four-piston pad is roughly rectangular and substantially bigger.
Road and gravel
| Your groupset | Pad you need |
|---|---|
| Dura-Ace R9170/R9270, Ultegra R8170/R8070, 105 R7070, Tiagra, Metrea, GRX | Flat-mount road and gravel pads |
Hope fitment
| Your calliper | Pad you need |
|---|---|
| RX4, RX4+, Mono M4 and E4 (2013 onward) | Hope RX4 and M4/E4 pads |
| Tech 3 V4, Tech 4 V4 | Hope V4 pads |
A warning specific to Hope: the Tech 3 and Tech 4 names refer to the lever, not the calliper. A Tech 4 lever can be paired with an E4 or a V4 calliper, and those take different pads. Check the calliper body, not the lever.
Hope have also reused the M4 and E4 names across more than one calliper generation. If your brake predates 2013, compare the old pad against the photos before ordering.
Choosing a compound
The pad material matters more than most people realise, and the trade-offs are real.
Organic (also called resin) is the quietest and gentlest option. It bites well from cold and it's kind to rotors. The downside is heat: organic pads fade on sustained descents and wear quickly in the wet. Fine for commuting and general riding on flat ground.
Semi-metallic mixes metal particles into the resin. You get stronger bite, considerably better heat tolerance, and longer life, at the cost of a little more noise. For most riders, most of the time, this is the right answer — which is why it's what we fit as standard across the range.
Sintered (fully metallic) is all metal, bonded under heat and pressure. It lasts longest, handles water and mud best, and tolerates serious heat. It's also noisy, slow to bite when cold, and wears rotors faster. Popular with downhill riders and anyone riding in genuinely filthy conditions year-round.
Carbon compounds sit alongside semi-metallic but hold their performance better once the brake is properly hot. We offer them on the four-piston and road pads. Worth the extra couple of pounds if you ride long descents, ride loaded, or run an e-bike. For everything else, semi-metallic is plenty.
A note on e-bikes
An e-MTB can weigh twenty-five kilos before you sit on it. That mass has to be dissipated as heat through the same pads fitted to an analogue bike. If you ride an e-bike, go up a compound and check your pads more often than the manual suggests.
When should you replace them?
The friction material is the layer bonded to the metal backing plate. When it wears down to roughly 0.5mm, replace the pads. Total pad thickness including the backing plate should never get below about 1.5mm.
Easier signs to spot on the bike:
- A grinding or scraping noise means you're already into the backing plate. Stop riding and replace them now, before you need a new rotor too.
- The lever pulling closer to the bar than it used to. This can also mean the brake needs bleeding, so check the pads first.
- Weak braking that doesn't improve after bedding in.
- Any oil or brake fluid on the pad. Contaminated pads cannot be cleaned reliably. People try sanding them, burning them off with a blowtorch, washing them in solvent. It doesn't work — the oil has soaked into the material. Replace them, and find the leak first, or you'll contaminate the new set too.
Road pads are small, so there's less material to lose. In a British winter, grit and salt turn a wet rotor into grinding paste and a set that would last a summer can be finished in six weeks.
Bedding in — don't skip this
New pads feel disappointing until they're bedded in. This catches out a lot of people, who conclude they've bought badly when they've simply not completed the fitting process.
Bedding transfers a thin, even layer of pad material onto the rotor. Until that layer exists, you're braking metal against fresh compound and it won't bite properly.
How to do it: find a quiet stretch of road or a gentle slope. Get up to a moderate speed, brake firmly but not to a complete stop, and release. Repeat around ten times. The brake will feel progressively stronger as you go. Let everything cool before your first proper ride.
Two things to avoid: don't drag the brake continuously instead of doing distinct stops — that glazes the pad. And don't come to a complete standstill while the rotor is hot with the lever held, which deposits material unevenly and causes a pulsing feel later.
Common mistakes worth avoiding
Replacing only one end. If the front pads are worn, the rears usually aren't far behind. Doing both saves a second workshop session.
Touching the braking surface. Finger grease is a contaminant. Handle new pads by the backing plate.
Mixing compounds front and rear. It works, but the bike will brake unevenly and it takes a while to trust. Keep them matched where you can.
Forgetting the rotor. A rotor worn below its minimum thickness — usually stamped on the rotor itself, often 1.5mm — won't be saved by new pads.
Still not sure?
If you've checked the calliper and you're still uncertain, send us a message with your brake model or a photo of the calliper and we'll tell you which pads you need. We'd rather spend two minutes on that than process a return.
We make our pads under our own name, which is why they cost a fraction of the branded equivalents for the same fitment. No distributor sits between us and you.