Semi-métalliques vs organiques vs céramiques

Brake pad compound selection is usually presented as a quality hierarchy — organic at the bottom, ceramic at the top. That framing is wrong. Each compound is a set of trade-offs, and the right choice depends on how the bike is ridden.

Organic

Organic compounds use a lower metallic content, which makes them gentler on the disc and quieter in normal use. Initial bite at low temperature is good, which suits a bike used at low speed in traffic.

The limitation is heat. Organic material fades earlier, and on a long descent with a loaded bike the lever goes long before the pads are worn. They also wear faster, so the cost per kilometre is higher than the purchase price suggests.

Semi-metallic

Semi-metallic compounds trade a little cold bite for a much flatter friction curve at temperature. This is the compound that suits most riders of larger or heavier machines, and almost any application where the bike is loaded or ridden on hills.

Disc wear is higher than organic, and cold performance in wet weather is slightly behind a good organic pad for the first few applications. Both are acceptable for street use.

Ceramic

Ceramic compounds are quiet, produce less dust, and hold their friction level well at moderate temperatures. They are an excellent choice for a bike ridden calmly in dry conditions.

They are a poor choice for sustained hard braking, because the heat path is different and the pad can glaze. Ceramic is also unforgiving of a warped or worn disc, since the pad is less able to conform to it.

Matching compound to use

• Commuter, city traffic, low speed: organic, or a mild semi-metallic if the rider carries a passenger regularly.
• Mixed use, hilly terrain, occasional passenger: semi-metallic. This is the safest default for a general-purpose street bike.
• Touring, dry climate, calm riding: ceramic, with the caveat about sustained descents.
• Track or aggressive riding: none of the three compounds above is the right answer; that application needs a dedicated high-temperature material and matching discs.

The part buyers get wrong

Buyers often compare compounds by price per set across a range, then stock the cheapest one across all fitments. That works until a customer fits the cheap pad to a heavy bike and returns it as "brakes are weak" — a complaint that cannot be resolved without changing the compound, and which costs more in handling than the margin on the sale.