AI quick summary
- Resin (organic) pads are quiet, bite well from cold, and are gentle on rotors — but burn up under sustained heavy braking.
- Sintered (metallic) pads survive high temperatures and long descents but need heat to bite and are noisier in the dry.
- Semi-metallic pads split the difference and are the safe default for mixed-condition riding.
- Bedding-in — a series of controlled hard stops from speed — transfers an even pad film onto the rotor and is the difference between a brake that works and one that howls.
/ 01
What a Brake Pad Actually Is
A brake pad is a block of friction material bonded to a steel backing plate. The backing plate is what the caliper piston pushes against; the friction material is what touches the rotor. The compound — the recipe of that friction material — is the single biggest variable in how a brake feels, sounds, and performs.
Three broad compound families dominate cycling: resin (also called organic), sintered (also called metallic), and semi-metallic. Within each family, manufacturers blend in graphite, ceramics, Kevlar, copper, and other fillers to tune bite, heat range, noise, and rotor wear. But the family is the dominant factor — pick the right family first, then the model.
/ 02
Resin Pads: Quiet, Cold-Biting, Fragile
Resin pads use a binder resin mixed with organic fibres, rubber, and sometimes a small amount of metal. They are the softest compound, the quietest, and the gentlest on rotors. Their standout trait is cold bite — they grip the rotor immediately from the first lever pull, with no need to warm up. This is why resin pads come stock on most road and gravel bikes.
Their weakness is heat. Above about 400 degrees C the resin binder begins to break down, the pad surface glazes, and friction falls off a cliff. On a long alpine descent a resin pad can be destroyed in a single pass — the friction material literally smokes and crumbles off the backing plate. Resin pads also wear faster in wet, gritty conditions, because the soft compound is more easily abraded by road muck.
/ 03
Sintered Pads: Hot-Surviving, Loud, Long-Lasting
Sintered pads are made by pressing metal powder — usually bronze or copper based — into a mould at high temperature, fusing it into a porous metal block. They are the hardest compound, survive temperatures above 800 degrees C without complaint, and last roughly twice as long as resin in abrasive conditions. They are standard on enduro and downhill mountain bikes.
The trade-off is twofold. First, sintered pads need heat to bite — the first stop in a cold descent feels weaker than the third one. Second, they are loud. Wet sintered pads howl, dry sintered pads squeal under light pressure, and the noise is a frequent source of forum complaints. They also wear rotors faster than resin — the metal-on-steel interaction is more abrasive than resin-on-steel.
/ 04
Semi-Metallic: The Middle Ground
Semi-metallic pads blend resin binder with a higher metal content — usually 30 to 50 percent by weight — and add moderating fillers like graphite or ceramic. The aim is to keep the quiet, cold-biting nature of resin while extending the heat range and wear life closer to sintered. The result is a pad that does nothing exceptionally but everything competently, which is exactly what most riders need.
Most manufacturers now offer a semi-metallic option as the default fitment on mid-tier brakes. Shimano's resin pads with cooling fins — the Ice-Tech line — lean on fin area rather than compound alone to survive long descents, which is a different engineering solution to the same problem.
/ 05
Compound Decision Matrix
Pad compound by riding type and condition
| Compound | Cold bite | Heat limit | Noise | Rotor wear | Best for |
|---|---|---|---|---|---|
| Resin / organic | Excellent | ~400 C | Low | Low | Road, gravel, dry XC |
| Semi-metallic | Good | ~600 C | Medium | Medium | Mixed-condition all-round |
| Sintered / metallic | Needs warm-up | 800 C+ | High | High | Enduro, downhill, alpine |
/ 06
Bedding In: The Step Most Riders Skip
A new brake pad is not ready to use. Out of the box the rotor and pad surfaces are smooth and contaminated by manufacturing residue. Bedding in is the process of transferring a thin, even layer of pad material onto the rotor, and it is the difference between a brake that works silently for months and one that howls after a week.
The procedure is simple: from a moderate speed (around 25 km/h), brake firmly to a near-stop without locking the wheel. Repeat ten to fifteen times per brake, allowing a brief cool-down between stops. The rotor will warm up, the pad will deposit material evenly, and the brake will feel progressively firmer. Avoid long, hard stops during the first fifty kilometres — a panic stop on a brand-new pad glazes the surface and ruins the bed-in.
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