Bike brands have to make a lot of difficult decisions when picking exactly which components they’ll spec on a given model. There’s always a price point that needs to be met and profit margins that need to be satisfied. It’s no surprise that, on a large production run, a difference of just a few pennies in wholesale pricing can start to become pretty important. That’s why you’ll sometimes see odd choices like brand-X cassettes paired with name-brand derailleurs, a single-size dropper post specced on every size frame, and today’s topic, adequate brakes running on inadequate rotors and pads.
We’re focusing on rotors and pads because upgrading the entire braking system may not be necessary to get you the power you need. Especially on more affordable bikes, brands often choose pad and rotor spec that will get the job done for
most riders, but maybe not for
you. We’ll break down a little about the difference between the variety of pads and rotors you have to choose from, and what you need to keep in mind when you’re ready to hop up your stoppers.
Pad materialBicycle disc brake pads are divided into two categories. There are ‘organic,’ also known as resin, and there are ‘metallic,’ also known as sintered. Organic pads are usually a mixture of fibrous particles bonded together by a resin glue, while metallic pads are made of metallic particles that are compressed and bonded together with heat. On the trail, organic pads tend to be a bit quieter, but they are less effective in the wet and will lose power as they heat up under prolonged braking. Metallic pads work great in the wet, and do well when subjected to prolonged heat buildup, but they are more likely to be noisy, though that’s rarely severe enough to overshadow their benefits. They also are harsher on rotors over time, and some lower-priced bikes come with rotors that can not be used with metallic pads.
Though this is not always the case, lower-priced bikes tend to come stock with organic pads. The dry, cool-temperature, moderate-speed performance of metallic and organic pads is very similar, but organic pads tend to give the brake a slightly softer feel at the lever. If that bothers you, or if your descents are prolonged and steep, swapping to metallic pads is an inexpensive way to improve your brake performance as long as your rotors are compatible. If the rotors are not compatible, they will almost always be laser-etched somewhere indicating they are for “resin pads only.”
Identifying the pad material is sometimes more difficult. Most brands will identify a pad’s material by stamping it in the metal backplate, but not always. There is no reliable way to go by color or texture to identify metallic or organic pads. Metallic pads may have some shiny or reflective particles, but if an organic pad has been used, there may be specks of material smooth enough to reflect light like metal. Some organic pads use an aluminum backplate, which you can identify easily because it is not magnetic. Some metallic pads use titanium backplates which also are not magnetic, but this is extremely rare.
If you have no visual clues which pads you have, go by your experience. If your brakes tend to lose power, or ‘fade,’ on long descents, it is possible that they are organic, and a $20 to $30 (per wheel) trip to the bike shop is a good place to start. In the case of some entry-level Shimano brakes or on brands like Tektro or Promax, the brake manufacturer may not make metallic pads for your particular brake, but there are third-party manufacturers like EBC, Clarks, Galfer or Jagwire who likely make metallic options for your pad. Just make sure you follow their guide for picking the right pad because many look similar.
If heat buildup is indeed the problem you’re facing, Shimano has introduced the pads you’re seeing in these photos, with aluminum heat sinks that dissipate heat into the air with an increase in surface area. All but the most entry-level Shimano brakes can be fitted with on-brand heat sink pads. Aftermarket brands like Kool Stop and Swisstop may make a heat-sink pad for your brakes if you are finding a drastic loss of power after your brakes have built up extreme heat on a prolonged descent. Just keep in mind that heat sink, or ‘finned’ pads tend to rattle in their calipers, enough to be a deal-breaker for some riders.
Whenever working with rotors and pads, be sure to keep them away from oil and wax, as the pads are porous and can get ruined if they are contaminated. Always wipe off the rotor with alcohol and a clean rag after handling it.
Rotor materialIf you are swapping rotors in order to change to metallic pads, it’s simple to tell if it’s necessary on major brands Shimano and SRAM (possibly branded as Avid, depending on your bike’s age). Shimano rotors will always indicate if they are resin-pads only, and SRAM does not make resin-only rotors. It is not as simple on other brands of brakes. If it is not written on the rotor, you may be able to tell by looking closely at the rotor itself. Less expensive resin-only rotors are usually manufactured by being stamped, not machined, and you can tell by looking closely at the edges of the rotor material. If they are sharp, square edges, it is likely a higher-quality rotor and you’re free to use the pad of your choice. If they are slightly rounded or chamfered, you may have a resin-only rotor.
But that is definitely not the only reason you might want to change rotors. The easiest and cheapest way to increase the power in your braking is to swap to a larger-diameter rotor. The three most popular diameters are 160, 180 and either 200 or 203 millimeters (some brands use 200, some use 203, and no, that doesn’t really make sense but we’ve gotten used to it).
There are a few 140-millimeter rotors in the lightweight cross-country and gravel market, and a growing number of 220-millimeter rotors in the downhill and enduro market. A larger rotor gives the brake caliper more leverage against the wheel, simply offering more power. It also provides more surface area to distribute the heat buildup, leading to less fade. But larger rotors are heavier, and are easier to slightly bend if they come in contact with objects on the trail or if the bike is not carefully transported, though most riders with large rotors consider it worth the risk.
Before increasing the size of your rotor, keep in mind that some frames and forks have a maximum rotor size. If it is not indicated on the component itself, it is safest to check with the manufacturer.
Your rotor size will be stamped somewhere on the rotor itself. Most bikes, just like most cars, will run a larger rotor in the front where there is the most potential braking power and a smaller rotor in the rear where too much may just send you skidding. If you are finding yourself putting enough force into your brake levers that your hands and forearms are becoming fatigued, but you are still not slowing down quickly or consistently enough, or if you are experiencing brake fade despite running metallic pads, it is probably time to go to larger-diameter rotors.
Rotor diameterThere are two ways that rotors can be attached to the wheel. The vast majority use six small bolts, but Shimano introduced a system called Centerlock, using one large hollow ‘bolt’ concentric with the axle. This requires a special tool to change. If that large hollow bolt is notched on its inner surface, you need what is often called a ‘cassette lockring tool.’ If it is notched on the
outside, you will need a 16-notch 44mm bottom bracket tool. If you have Shimano brakes, it may be equipped with either system, but nearly every other brake brand will be six-bolt, which requires only a T25 Torx wrench, and it is likely on the tool you already take on the trail.
Once you’ve gotten the right rotor interface, and you know your frame or fork can handle it, all you need is the correct caliper adapter to position the brake itself out on the larger diameter rotor. For several years, there has been one standard on forks and frames called ‘post mount.’ These threaded ports will usually default to a 160mm rotor, meaning the brake caliper will bolt on directly with no adaptor if you are using a 160mm rotor. On more aggressive, gravity-oriented frames and forks, they may default to a 180mm rotor.
Finding the adaptor you need is simple arithmetic. If you have a 160mm post mount and you want to install a 200 or 203mm rotor, you need a 40 or 43mm post-mount adaptor and the accompanying bolts, which will come packaged with the adapter. If you have a 180mm post mount, you will be looking for a 20 or 23mm adapter.
Again, the brakes themselves can be upgraded, but that can quickly become a several-hundred-dollar job, whereas a larger rotor and adapter may only cost $50 per wheel, and different brake pads may be even less. And the best part is, these swaps only require simple tools and minimal experience in wrenching on your bike.
Also MTB's roots is not embiggened BMX stuff, it's beefed up beach cruisers and road bikes.
What's pretty funny is Decathlon have a Giro flat pedal shoe on their website and they are describing it as clipless!!
I'm not sure how many ways wrong this is anymore ...
They were used by some on some bike but weren’t the roots.
I remember doing the lollipop route in Torridon this summer (so the weather was horrendous). I checked the pads the night before: half way through, I'll be OK, I thought......
Ended up with no brakes 300 mts before the end of the descent!!!
Ordered 8 more pairs from Germany the day after that.
Oh, and Brexit is shite.
But yeah, modern resin pads are amazing and so much better than older compounds.
Even magura race pads lasted 6 times of the trickstuff, should've bought galfer
I've heard good things about them.
I just eyeball it. If you can see a gap between the pad and rotor on each side you’re good
"Look at that subtle colouring. The tasteful thickness."
His face creases in horror.
"Oh my God. It even has a watermark."
On the trail, or in the wilds in general?
Not so much.
6 bolts rotors can be swapped anywhere with even the cheapest multitool. CL can't. You need a wrench and a bb nut.
In my humble opinion. 6 bolt is the far easier design than cl.
Just my 2 cents.
because of this, I've never had play in the Centerlock splines as well. Thats another plus for CL, you only need to check torque on one nut (40nm) and not 6 tiny bolts (4-6nm). More torque = more better.
All the people talking about trailside repair, is there anyone who takes a spare rotor on a ride with them? Even if you are on a road trip and you've brought a spare rotor, its 100% going to be in your vehicle. If you've thought that far ahead, you probably have a decent tool kit with you and the proper CL tool for the style on your bike.
On center lock, the room seems to be split, but I know far more people who have never had one come loose than people who have. Some mechanics say they see it occasionally, others say they never see it.
Haha well don’t go out of your way but that would be definitely cool to see.
m.pinkbike.com/photo/23794796
He's also 6'11, 275+ lbs, and pretty fast. I imagine he puts a lot more force on brake mounts than most.
I think I found the problem.
Never had an issue with thickness
All brake pads (believe it or not) are the same thickness, with very-slight variances. 2mm of backing plate, 2mm of compound material.
BTW: I stopped bying the overpriced ventilated XT pads + the Ice-Tech rotors. Saint pads and normal (metal) XT pads are half the price and they perfectly do the job added to some cheap SLX-Zee RT66 rotors. Cheers!
It's also possible that you just have much too small rotors (and/or calipers) for your riding. This article is just completely full of ambiguous "it might be" statements that provide literally zero help. Might as well just flip a coin to figure out what your brake setup is, instead of following this joke.
Yeah I would have liked to have seen a bit more about different rotor thicknesses, floating designs, shimano ice-tech rotors etc in this article. And maybe a little more on the various pad compounds available. But I'm certainly not complaining about articles like this getting more common
There were so many "sometimes this means that" statements that it didn't answer any really questions. "How do I know if I have resin pads?" "Well, you can check for non-magnetic back plate, but sometimes resin has steel and sometimes sintered has aluminum." "Oh, well then that doesn't help really at all, I'll just know if my backplate is steel or not."
So you effectively need a "+40" to go from 160mm to 200mm disc
Brakes are soooo personal.
That said, before hating on your brakes try different pads. Maybe a bigger rotor. Then start looking.
What I wanna know what I really wanna know is how it is that pads can become contaminated so easily. We have had several bikes (customers and our personal bikes) have pads become contaminated literally just sitting overnight in the shop. I'd pay a bit more for pads that had a no contamination guarantee. Not possible I know but since we are dreaming about perfect brakes....
Just tell this to Shimano. They started with the SLX, then now also the XT rotors are stamped and made in China, while a few years ago both SLX and XT were laser-cut rotors.
BTW, thx Shimano, for lower quality at a higher price!
I've swapped the adapter ofc (203->200mm) but the wear marks indicate that not the full rotor brake area is used. It *seems* that the wear on the pads is correct, but I experience a slight gobble feel esp. when I brake harder at slower speeds. In the meantime I have found a couple of rotor pictures of a full SRAM setup and it seems that there is an unused braking area as well of some 2mm (hazard guess), innermost area.
As for resin vs sintered, things may have changed but I thought all Magura brake pads are resin. They have endurance and performance pads, but they're all resin. They're not supposed to get that hot anyway as their oil has a lower boiling point than the competition, so maybe that's why resin is less of an issue for them.
Similar story with copper coated backing plates on sintered pads, they wear out the pistons.
B) I didn't see mention of the fact that Shimano has narrow and wide pads. Make sure that your rotor surface is compatible with the pad face, and that your pad does not extend past the braking surface.
Here is the pad rotor comatability chart.
shimanobikes-nz.prontoavenue.biz/ts1570079501/attachments/Page/20/Disc%20Brake%20Pad%20Compatibility%20Chart.pdf
Semi-metallic? Ceramic? And "resin/organic" is basically a category in itself, because modern resin compounds are so much better than older ones, and quite varied as well. It's pretty old-skool slash wrong to generalized about resin pads the way this article does.
The other thing to keep in mind is going the next rotor size up, usually yields about a 10% improvement in torque, but pad compound is far more sensitive. You find 2 piston brakes that have more power than a 4 piston brake. The problem is, the pad shapes are usually unique so you get locked in. If you want good pads, you have to buy brand X brakes.
But would love to give it a listen
I’m currently being impressed by swisstop silver resin but i’ve not checked the wear lately
Amazon it is I guess. Unrelated, we did a day trip to Grenoble a few weeks back (if that's where you currently live). Nice town, will visit again to see if I can find a car-less way to any trails. Also sounds like a good place to stage for a shuttle to Alpe d'Huez...want to eventually try that on the road bike.
There are alot of trails that you can access without car. St nizier, frange vert, mont rachais and 4seigneurs. For those far away, just put it in the bus rack, thats how I get to seigliers-chamrousse, st nizier, 7laux. For the return you just need to go down the mountain.
Or you could tell for real by just looking for the "resin pads only" etching. SRAM and others have been putting chamfers on at least the outer edge of normal rotors for a bit now. That advice is like saying "if your truck is tan, you might have a Toyota".
Who else beyond Shimano even makes resin-only rotors?
Here's what works well enough to never have to write this article again (although I imagine there's been a push to solicit beginner pieces to become some sort of "one place on the web for information, experience, and community" or whatever the autoplay overlords said in the meeting) - four (4) piston hydraulic brakes. Metal pads. 8 inch rotors (which is where the 203mm comes from, ya dingbats). Let's move on!
*uh-oh, I forgot we have to drop the employee with the head injury somehow... seen that too.
ROBIN: your thoughts!
But hell, I guess on a lot of bike park trails you can get off the brakes for almost the whole thing, and they handle speed well even when steep and rough. So if you’re not having issues then that sounds like a sweet deal. But riding really steep rough cut trails with off camber unsupported corners where slowing down quickly is essential, the low end stuff just doesn’t work for me. I end up having to ride slower because I can’t shut it down when I need to.
And so do some sintered pads, so that's a useless thing to check.
Simple math not so simple, apparently, silly goose. Look up the difference between diameter and radius, and then think real hard about it.
Not to mention that most adapters offset the caliper in some way in addition to spacing them out, so nobody should be choosing an adapter by measuring it's thickness.
Real quality stuff y'all are putting out here pinkbike.