By fitment reference, published by the pad maker. The backing plate shape, the pin hole positions and the thickness are specific to a caliper. A pad that is nearly right does not go in — and one that goes in but sits proud is worse.
What the reference is
A published list of the machines, or the original part numbers, a pad replaces. It is the specification. A listing that names a machine without a reference has left out the part that decides fit, and calipers are shared across models in ways a model name does not reveal.
Front and rear are different pads
Obvious once said, and a common ordering mistake — as is assuming both front calipers take the same pad on a machine with twin discs. The reference distinguishes them.
Then, and only then, the compound
Sintered pads bite hard, work well wet, tolerate heat and wear discs faster. Organic pads are gentler on discs, quieter and progressive, and fade sooner under sustained hard use. Two behaviours rather than two grades, and several machines leave the factory with one at the front and the other at the rear.
The compatibility line that overrides preference
Some discs are specified by their maker for organic pads only — certain cast iron and certain coated discs among them. Where that instruction exists it settles the compound question regardless of what would otherwise suit your riding, and it comes from the disc maker.
What happens after fitting
New pads do not work at full effect until they have been bedded in, and the procedure is published by the pad maker for that pad. Caliper fastener torques are in the machine’s manual. This site points at both rather than rewording them.
Where this page and the manufacturer’s own paperwork say different things, the paperwork wins. Every weight, shell size, armour level, approval version, viscosity grade, chain pitch, pad reference and torque figure on this page comes from the maker’s own published figures, with the unit as printed and the source named. None of it is measured here, and no figure is converted into another convention, because a converted number is a different number. And the limit this page does not cross: nothing here replaces the maker’s bedding-in, torque and pressure figures. New pads do not work at full effect until the procedure their maker publishes has been followed, a fastener has a torque its maker specifies, and a tyre has a cold pressure the machine’s manufacturer sets. This page points at those documents rather than rewording them.
Questions riders send in about this
Can I mix compounds front and rear?
Manufacturers do it from the factory. What matters is that each pad matches its own caliper reference and that the disc accepts that compound.
Do pads have a shelf life?
Makers publish storage guidance for the resin-bound types. It is one of the questions the packaging answers and a comparison page should not.
Last reviewed 18 September 2026