The short answer
- It's two decisions, not one. Your caliper decides the shape — get that wrong and the pad physically won't fit. The compound is the part you actually choose.
- Resin and organic are the same thing. So are metal and sintered. Shimano says resin and metal; SRAM says organic and sintered. Same two families, different vocabulary.
- Organic/resin: quieter, more bite from cold, shorter bed-in — but wears faster and doesn't like wet and mud.
- Sintered/metal: handles heat and wet far better — but louder, longer to bed in, less initial grab.
- Changing compound means a new rotor. SRAM calls it crucial. That's the cost nobody budgets for.
- Worn out is 0.5 mm on Shimano and 3 mm on SRAM — because the two are measuring different things. Don't carry one brand's number across to the other.
Someone puts a used brake pad on the counter and asks which one they need. It's two questions wearing one coat. The caliper on your bike decides the shape — that part isn't a preference, it's a fitment. The compound, resin or metal, is the bit you get to choose, and it's the bit that changes how the bike feels on a wet descent off Chappies.
Here's how to get both right, using what SRAM and Shimano publish themselves rather than what the internet reckons.
Shape first — your caliper decides this, not you
SRAM is blunt about it: "Each SRAM caliper needs a specific pad shape for proper fitment and safe, optimal performance. SRAM brake pads are available in Small Asymmetric, Small, Medium, Large, and Extra-Large sizes."
Five shapes, and the caliper picks one for you. Here's the whole map.
Shimano does the same job with letters instead. A B pad is the wide one that goes in its entry-level two-piston calipers. A G pad is the narrow two-piston shape used across Deore, SLX and XT. A D pad is one of its four-piston shapes. The number that follows — 03, 05 — is the compound generation, and it's worth knowing that Shimano publishes an actual figure for the jump: an "05" pad is "more durable than '03' pad in the same type by 40%".
Two of the Shimano pads we keep on the shelf are that 05 compound — including this one.
The B05S is the wide pad. Shimano lists it as standard fitment for the BR-MT500, MT400, MT410 and MT200 hydraulic brakes, plus the cable-operated M375 and TX805 — which covers a lot of the hardtails and commuters that come through the door.
The D03S is a four-piston pad: standard on BR-M7120, M6120, M6220, MT620, MT520 and MT420, and an option on the XT and XTR four-pistons. Worth knowing that four pistons alone doesn't settle it — Shimano makes several four-piston shapes, and the finned ones fit different calipers again. Match the caliper code, not the piston count.
Not sure which you've got? Don't guess from the bike's model year. Pull the old pad out and match it against the shape — SRAM will even let you print its identification chart at 100% scale and lay the pad on the page. Or bring the wheel and the bike in and we'll read the caliper.
Resin or metal — what the two makers actually say
First, the vocabulary, because it trips people constantly. Shimano's own explainer says resin pads are "also referred to as organic or semi-metallic pads… made from a mix of fibers bonded together by a strong adhesive", and that metal pads are "sometimes called sintered… made from metallic particles fused together".
So: resin = organic. Metal = sintered. Two families, four words, and nobody is being clever.
Shimano publishes a rating for its own pads across five axes, which is about as close to a straight answer as you'll get from a manufacturer.
Read that carefully, because it isn't the story most people expect. Resin doesn't lose on durability — Shimano rates the two the same. What resin loses on is anti-fading, which is heat, and it wins on modulation and quiet. Shimano's own description of the feel: "Metal brake pads have a more aggressive bite, with a definitive on-off brake feel. Resin pads have a more modulated, ramped feel, which is good for riders who want maximum control over the amount of braking power."
SRAM splits it the same way on its identification chart. Organic pads are the "QUIETEST", with a "SHORTER BED IN PERIOD" and "MORE INITIAL BITE" — but they "WEAR QUICKER" and are "NOT AS GOOD IN WET / MUDDY CONDITIONS". Sintered pads "FRICTION FADE AT A HIGHER TEMPERATURE THAN ORGANIC PADS" and give "BETTER PERFORMANCE IN WET CONDITIONS", at the cost of being louder and slower to bed in.
We keep both SRAM compounds in the large size, so you can see the difference in your hand.
⚠️ Before pasting: open each image and confirm it shows the product the surrounding section is talking about. A card that does not illustrate its section is evidence against the post, not for it.
A trick worth knowing
You can identify a SRAM compound by the colour of the backing plate, without a part number. SRAM's code: copper is sintered, black is quiet organic, grey is powerful organic and bare aluminium is the lightweight organic. Look at the two photos above — the sintered set is unmistakably copper, the organic set black. That's the whole test.
What that means on Chapman's Peak in July
This is where the generic advice stops being useful and local riding takes over.
Chappies is, by the road's own account, a "9km route with its 114 curves". That's not a descent you point down and let run — it's a hundred-odd brake applications in sequence, with the pads never really getting a chance to cool. Suikerbossie on the way back is shorter and steeper. Add a wet Cape winter and grit off the mountain, and you've built the exact case both manufacturers describe.
SRAM names it almost word for word: sintered pads are "ideal for heavy or extreme duty applications, where resistance to higher temperatures is required, like a steep sustained descent", and they "excel in all conditions, especially in wet and muddy environments". Shimano agrees on the weather: "the primary reason to go with metal brake pads comes down to weather conditions… Metal pads will last longer under these conditions, saving money and extending service intervals."
If you ride Chappies and the mountain through winter, I'd run sintered and put up with the noise.
And I'd be honest that it is noise you're putting up with — sintered pads squeal when they're wet or cold, and they don't grab as hard on the first pull until there's some heat in them. If your riding is mostly dry, mostly flat, and you can't stand a squealing bike, resin is the better pad and I'd say so. That's a genuine preference, not a downgrade.
One thing not to do: don't assume you know what's already in there. SRAM's own note is that "Code models come with sintered pads and G2, Guide, and Level models are originally equipped with organic pads. However, some bike manufacturers equip their bikes with different compounds." The bike brand can override the brake brand. Check the backing plate.
The rotor nobody budgets for
Here's the part that catches people out, and it's the reason a pad swap sometimes costs more than a set of pads.
If you change compound, you should change the rotor at the same time. SRAM: "When changing brake pad compounds, it is crucial to replace the rotors as well to achieve optimal performance with your hydraulic disc brakes. Introducing a new pad compound to a used rotor can create noise and reduce brake performance."
The reason is physical, not commercial. During bed-in, SRAM explains, "a thin layer of brake pad material is transferred onto the rotor. This friction between the two surfaces enables powerful braking." Your rotor is already wearing a film of the old compound. Put a different compound against it and the two fight — that's the noise and the lost power.
The bit that surprises even experienced riders: this can bite you within organic. SRAM again — moving between "Quiet/Organic pads and Powerful/Organic pads (gray backing plate), in either direction, requires rotor replacement", while quiet organic to lightweight organic is fine. Both are organic. One needs a new rotor, one doesn't.
So if you're switching, budget for the rotor as well as the pads. If you're staying on the same compound, you don't need one.
How worn is worn?
Both makers publish a number, and this is the single most useful thing in this article: the two numbers are not interchangeable, because they measure different things.
Shimano's is a safety instruction, not a suggestion — from the dealer's manual for its Deore-class hydraulic brakes: "Check the thickness of the brake pads and do not use them if they have a thickness of 0.5 mm or less."
SRAM's, from the G2 RE service manual: "Brake pads must be replaced if the total thickness of the backing plate and pad friction material is less than 3 mm."
Don't mix the two up
SRAM's 3 mm includes the steel backing plate. Shimano's 0.5 mm doesn't mention one. Measure a Shimano pad against SRAM's number and you'll bin a pad with plenty of life in it; measure a SRAM pad against Shimano's and you'll ride it down to the backing plate. Use the number that belongs to the pad in your hand.
While you're in there, check the rotor too. Shimano's limit, from the same manual: "Do not use the disc brake rotor if its thickness is 1.5 mm or less. Also do not use it if the aluminum surface becomes visible." A worn rotor eats new pads, so replacing one without the other is a false economy.
Bed them in, or you've paid for nothing
New pads don't work properly out of the box, and this is where most of the my new brakes are rubbish complaints come from. SRAM's procedure is specific and countable, and its service manual says it should happen "prior to your first ride":
- Stay seated. Don't lock the wheels up at any point.
- "Accelerate the bike to a moderate speed, then firmly apply the brakes until you are at walking speed. Repeat approximately twenty times."
- "Accelerate the bike to a faster speed, then very firmly apply the brakes until you are at walking speed. Repeat approximately ten times."
- Let them cool before you ride properly. The caliper may need re-centring afterwards.
Thirty stops. It takes about ten minutes on a quiet road and it's the difference between brakes that work and brakes that don't.
SRAM's own three-minute walkthrough of the procedure, from its SRAM TECH channel — the one its support pages point riders at.
SRAM attaches a crash warning to it, and I'd take it seriously: "If you are unfamiliar with the power and operation of disc brakes, you should have the bed-in process performed by a qualified bicycle mechanic." That's SRAM's line, not our sales pitch — but it is what the workshop is for.
If you're fitting them yourself — and you'll want a torque wrench rather than a guess — the two bolts a pad change tends to disturb have published figures. In Shimano's manual for the Deore-class brakes, the caliper fixing screws are 6–8 N·m and the centre-lock rotor lock ring is 40 N·m. Guessing at 40 N·m by feel is how rotors come loose.
Common questions
Which is better, organic or metallic brake pads?
Neither, and any shop that gives you a straight answer without asking where you ride is guessing. Shimano rates them equal on durability and splits the rest: resin wins modulation and quiet, metal wins power and heat resistance. For a wet Cape Town winter and long descents, metal. For dry, quieter, everyday riding, resin.
What is the downside of buying organic brake pads?
Two, in the makers' own words. They "WEAR QUICKER" and they're "NOT AS GOOD IN WET / MUDDY CONDITIONS". Shimano adds that organic pads fade sooner under sustained heat — its own rating gives resin three stars out of five for anti-fading against metal's five. On a long wet descent, that's the one that matters.
Should I get ceramic or organic brake pads?
Ceramic is a car-brake category. In the pad charts SRAM and Shimano publish for bicycle disc brakes there's no ceramic option at all — the choice is organic/resin or sintered/metal. If a listing offers you a "ceramic" bicycle disc pad, it isn't a compound either of those two manufacturers recognises, and I'd want to know exactly what's in it before putting it on a bike.
What are the best types of disc brake pads?
The best pad is the right shape for your caliper, in the compound that suits your riding, bedded in properly. In that order. A top-end compound in the wrong shape doesn't fit, and the right pad skipped through bed-in will feel worse than the worn set you took off.
Not sure what's in your calipers?
Bring the bike in. We'll read the caliper, measure what's left on the pads and the rotor, and tell you what it actually needs — including if the answer is nothing yet.