5x DH World Champion Loic Bruni trusts 220mm rotors. Should you? Photo: Graeme Murray / Red Bull Content Pool
The howl of an overheated brake is terrible. Your ability to stop degrades. Your arms get pumped from frantically pulling the brake levers, hoping for more. The splines of your rotor develop a telltale blue-brown tinge and don't stop squealing.
It's better to not overheat your brakes in the first place. Yes, I could brake less. But I’m not some fearless pro downhiller (few of us are). I am an average rider who NEEDS to brake A LOT. So I choose to upsize my brake rotors, and it’s a mod I do on every mountain bike I own. In fact, switching to bigger rotors is also the cheapest way to increase the power of your brakes. Here’s why I think bigger (200-220mm) brake rotors are best, and why I’m not going back to anything smaller on my trail and enduro bikes.
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More Stopping Power Is Always a Good Thing
Moving too fast for the camera? You might need bigger rotors.
For some context, here are a few crucial details about me:
- I generally sit around 180-190 pounds
- I ride steep and fast trails on the Colorado Front Range
- I currently use SRAM Code, Shimano Deore XT 4-Piston, and Magura MT7 brakes
10 years ago, I started my mountain bike journey on a cross-country bike with puny 160mm rotors. It’s what my bike came with and I didn’t know any better. As I got more advanced, I started riding steeper, gnarlier trails and pushing my limits. One day, after an intense 10-minute descent, my brakes were absolutely howling and my arms were so pumped I struggled to open my hands and let go of the grips.
“You need bigger brakes,” my much more experienced friend said.
I listened, and bought a pair of adaptors and 180mm rotors. It was a revelation. The immediate benefits I felt were:
- I didn’t have to squeeze as hard to slow down so my arms got less pumped
- My brakes stayed consistent and didn’t get spongy or weak on long descents
- My brakes didn’t overheat and start howling like a dying goose
Why Do Bigger Brake Rotors Provide More Power?
220mm rotor (on the front) = more stop.
There are two basic reasons:
- Bigger rotors provide more leverage for stopping because the brake track is farther away from the axis of the wheel.
- Bigger rotors have more surface area to dissipate heat more effectively. Better heat management = more consistent braking.
Let’s consider a 200mm rotor vs. a 220mm rotor. The 220mm rotor increases the braking surface by 10%. According to SRAM, with all other conditions being equal, this increase in surface area will drop the temperature at the brake pad by 39°C during hard braking, which SRAM says will give you about 10% more braking power.
Why I've Gone to 220mm Rotors
Angel Fire — the place where I learned to love big rotors.
I stuck with 180mm rotors front and rear on my XC and trail bikes for a while (I like running the same size front and rear, but that's another story). Then, 5 years ago, I started enduro racing. I traveled to places like Trestle, Keystone, Angel Fire, Granby, Crested Butte, Durango, and Moab — all areas with big mountains and serious descents. My 180mm rotors were fine for putzing around, but when it came time to go fast and string together a long descent, they got fried.
I had to swap out my rear 180mm rotor twice in one weekend at Angel Fire, so I decided it was finally time to upgrade to 200mm rotors. Again, it felt like a revelation — less arm pump, more consistency, and no overheating. I was sold, and have put 200mm on all of my trail and enduro bikes ever since.
My brake rotor progression over the years: 180mm to 200mm to 220mm (banana for scale)
Now, after spending another few years on 200mm rotors, I’ve decided to take things a step further and upgrade to a set of massive 220mm rotors front and rear. 220/223mm rotors are currently the biggest rotors on the market, and right now you really only see them on dedicated DH bikes. But some pro enduro riders are jumping onto the big discs (see my favorite racer: Jack Moir).
I’m not putting 220mm rotors on some big travel enduro bruiser, but a Forbidden Druid, a 130/150mm travel trail bike. This might seem like overkill for a shorter-travel bike, but Lewis Buchanan also ran 220mm rotors during his time on Forbidden and said he really liked them. Why should my bike have less braking power just because it has less travel?
Honestly, my 200mm rotors felt great pretty much everywhere I rode, including downhill bike parks. I probably wouldn’t have thought about upsizing, if it weren’t for this one (secret) downhill trail near me. It’s the steepest, most terrifying trail I ride, and the only way for me to survive is to drag my brakes down the entire thing for 7-8 minutes. Not even my 200mm rotors can survive that sort of abuse.
I’ve done several rides on my 220mm rotors now. What are my findings so far? If you guessed less arm pump, more consistency, and no overheating, then you’re 100% right. My brake rotors keep getting bigger, and they just keep feeling better. If and when 240mm rotors become available, I’ll probably be the first in line to buy them.
Are There Any Downsides to Bigger Brake Rotors?
So I'm talking up dinner plate-sized brake rotors like they’re god’s gift to mountain bikers. So what’s the catch? Here are some of the major downsides of big rotors:
- They weigh more than smaller rotors
- They cost (slightly) more than smaller rotors
- They require brake caliper adaptors to install
- They can be easier to lock up
- They’re easier to bend/have less ground clearance
- Some bikes/forks aren’t approved for big rotors
Here’s a basic comparison of SRAM's Centerline 6-bolt rotors:
|
Size |
180mm |
200mm |
220mm |
|
Weight |
151 grams |
207 grams |
223 grams |
|
MSRP |
$53 |
$59 |
$59 |
Just going from a 180mm rotor to 200mm is a 37% increase in weight. That sounds big. But it’s “only” 56 grams per rotor. Keep in mind that it is rotating weight, which has the biggest effect on how much energy it takes to spin your wheels up. Will that matter to you? Well, that’s for you to decide. I certainly can’t notice it.
In regards to cost, the MSRP difference between different-sized rotors isn’t actually that big. In fact, the MSRP for SRAM’s 200mm and 220mm Centerline rotor is the same (and you can often find these on sale). In many cases, the difference between sizes will be less than $10. Well worth it for more braking power if you ask me.
But then there are the adaptors. You will need to get the correct adaptors to space out your calipers for them to work with larger rotors. This adds some weight, some cost, and also some complexity. Again, up to you if that matters.
Because bigger rotors increase braking power, they can also provide less modulation and be easier to lock up. This is true to an extent. But personally, I really don’t notice this. I could see an inexperienced rider grabbing a handful of brake and then skidding into oblivion. In my opinion though, most riders will quickly get used to modulating their brakes with bigger rotors.
The biggest downside I see is that bigger rotors tend to warp more easily from heavy use. They just require some more regular rotor truing to keep them from rubbing.
Bigger rotors also provide less ground clearance so they’re much more likely to strike rocks and other trail feature or bend if you crash. For me, that’s a fine trade-off.
Then, the final point is a notable one. Some bike frames and suspension forks might not be approved to run 200+ mm rotors. Always check with the manufacturer.
How Do You Decide What Size Brake Rotor to Run?
Many enduro bikes now come with 200mm front rotors. That's great! But is it enough?
My opinion is to just slap the biggest rotor possible onto your bike and be done with it. But what if you want some more nuance in your decision-making? Yes, while I love my big 220mm brake rotors, I do concede that they’re not for everyone. They are completely unnecessary for:
- Super lightweight riders
- Flatter or less technical terrain
- XC racing
If that describes you or your riding, then brake rotors in the 160-180mm range are probably more than enough for your needs.
Here’s my ultimate recommendation: run the rotors that give you confidence on the hardest descent(s) you ride.
For some, 180mm will handle everything they do with ease. But I think most riders who live somewhere with long and steep descents will appreciate the extra power of 200mm rotors.
For me though, there is that one trail where I alway wish for more. For that one use case, I’ve chosen to put 220mm rotors on my bike. They’re excessive everywhere else, but they don’t negatively impact the riding experience otherwise, so why not run them? Whenever I do get on that one terrifyingly steep track, I’m happy to have them.
I’ve never heard a mountain biker complain about having too much braking power. In fact, improving braking power is probably the most useful upgrade you can make to any mountain bike (after good tires that is). So go big! Enjoy the power.
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