Dropbell

Disc brake pads: sintered vs organic, and what to actually buy

Pads are the cheapest component that transforms how your bike feels — and the single best thing to stock up on when they're discounted.

The three compounds

  • Organic (resin). Fibres bonded in resin. Quiet, strong initial bite, work well from cold. Wear faster — especially in wet, gritty UK conditions — and fade sooner on long alpine-style descents. The default fit on most new bikes.
  • Sintered (metal). Metallic particles fused under heat. Slower to warm up and noisier, but last far longer in wet grit and keep working when brakes get properly hot. The pragmatic choice for a British winter.
  • Semi-metallic. The compromise: organic-ish feel, better durability. Where a brand offers one, it's a sensible year-round pick.

One hard rule: some rotors are marked "Resin only" — common on cheaper Shimano rotors. Sintered pads will chew them up. Check the rotor before switching compounds; a compatible rotor is cheap, a surprise is not.

Buying the right shape

Pad shape is specific to the brake caliper, not the bike or the lever. "Shimano pads" is not a spec — a 2-piston XT caliper and a 4-piston XT caliper take different pads. The reliable method:

  • Find the model printed on your caliper (e.g. Shimano BR-M8120, SRAM Code, Hope Tech 4 V4).
  • Buy pads listed for that caliper model. Reputable pad makers (manufacturer originals, plus aftermarket brands with good reputations) publish exact fitment lists.
  • Ignore "universal" pads. There's no such thing.

When to replace

Replace when the combined pad material (excluding the metal backing plate) is down to roughly 1mm, when braking develops a persistent metallic grind, or immediately if pads are contaminated with brake fluid or oil — contaminated pads never come back properly, whatever the internet says about blowtorches and baking. Bed new pads in with a couple of dozen firm stops from moderate speed before trusting them on a descent.

Why pads are the smart sale purchase

Pads don't expire on the shelf, they're consumed on a schedule (a wet UK winter can eat a set of organics in a couple of months of regular riding), and the shape your caliper takes won't change until you change brakes. That makes them one of the few components where buying multiples in a discount is simply rational. When Dropbell's alerts launch, a "below £X" watch on your pad shape is exactly the kind of boring, money-saving alert the service is built for.