Why THICK Rotors Will TOTALLY Change How You Ride (EASY Upgrade with REAL Proof) 

I followed your suggestions about two years ago and I have been super happy with your data and my first hand account. Thanks.

I've always loved the feel i get from 203mm rotors, both front and back and never gone smaller diameters again. Haven't had any fading situation with the brakes with different brake systems (shimano, sram and now hopes) with the 203s. Loving your rational take on the subject. Have a nice day!

I think this test would greatly benefit from testing with only new rotors, and with only rotors with the same design. I've tried several brands of rotors a decade ago and there were huge difference between some brake design, even in the same alloy.

Speaking from car experience, more mass means more heat asorbtion. But, one thing to keep in mind is heat dissipation. Larger diameter means more surface area. Which in turn will give faster heat dissipation. When it comes to brakes, you want the mass increase from diameter. Leverage, surface area and mass.

Really great video Matt! Been eyeing up better rotors lately and you just sold me on getting thicker ones ASAP. I tried a 220mm on front of my enduro bike and felt it was too much brake. Do you think it would be best to run a 220mm in the rear too to make it feel more balanced? I'm riding in your old stomping grounds (Blue Mountain, SALS, Glen Park). Dan

for ebikes, brakes seem to generally be undersized - not taking into account the higher mass of the bike and larger rotational mass of the usually fat tires. would be interesting to see what kind of temps they see when braking to a stop from 30mph. and how that is impacted by thicker rotors at the same diameter vs a larger diameter rotor of about the same mass as the thicker upgrade one. assuming a thicker one fits in the test bike. it's too bad rotors aren't forced to be sold with a wattage rating of how much they can peak absorb and how much they can constantly absorb at room temp. then you could estimate if it's good enough for your use fairly directly.

3x spoke lacing is the strongest because the spokes are the most tangent to the hub. It also has leading and trailing spokes so that there are always spokes in tension. I don't see much of that thinking in some of these rotors -- is the force distribution that different, or are they just making pretty patterns and assuming that the steel is more than strong enough?

I'm very interested to try these on my XC bike, running XTR M9020 so hopefully they will fit. Previously used any quite like the Galfer 1.8mm. Im also curious about the ZTTO 4 Piston brake set, have you tried them out at all or is that something to stay clear of?

It made a difference for me, but I’m a heavy rider at about 220 lbs (almost 100 kg).

That’s so cool! How are you tracking the brake data?

Hey Brutha. I received the Ali express 2.3 203 rotors. One of them has a very fine scratch on one side of the braking surface. Do you think I should ask for a replacement? Or will it not be noticeable once bedded? Thanks

Can I use thicker brake discs (2.3mm or 2.15mm) with my Sram Code R brakes, or can I no longer get the brake disc between the brake pads even if I push the pistons back? I'm currently driving the Centerline 220mm (2mm) at the front and Centerline 200mm (1.8mm) at the rear with a Fox 38 Factory, but I'm having problems with dragging brake discs due to deformation and bending. Especially when I drive on asphalt and accelerate hard, my front brake starts to drag. This is extremely annoying. The brake caliper sits in the middle and doesn't drag when standing. However, the gap between the brake disc and the pad is so small that not even a sheet of paper would fit between them. I'm not yet satisfied with the braking power and the pressure point of the brakes, but I still use the original Sram sinter brake pads. I also have to bleed the brakes very carefully again and hope that the pressure point and free travel will then improve.

I have been using ztto 203mm rotors since last year cheap and big upgrade to my braking.

Galfer 246 on my (recently stolen) ebike. Galfer green pads or MTX pads. Really helps with hand pump.

Will the thicker discs work with most calipers? I am about to build an 8000 watt emtb and think they would a good addition along with regen braking.

Great Video. Sorry if this has already been asked/suggested. Would be super interesting to see you use your tech to test whether Shimano’s Ice Tech rotors make much difference vs standard.

I feel like what you should be comparing is polar moment to heat dissipation or heat storage (or a combination of both - some type of overall performance). As you know, more weight doesn’t necessarily mean more energy to spin up, or on the contrary, exponentially more energy despite having a similar scale weight (scales to square power), but also I’d be curious at what point is a rotor too large. I would think that would be the whole point of the test - everyone knows a bigger rotor is going to have more surface area, have higher velocity at the edges, provide more leverage, etc etc. it’s at what point is a rotor too big that it become a detriment rather than a benefit.

On my 130mm trail bike with 203/180mm with 1.8mm thickness, on my 160mm enduro 203/180mm with 2mm. Besides thinkness also pad compound trail uses organic/resin, enduro was sinstered now ceramic

I agree, i went from shimano to magura rotors and have never gone back...thicker rotors allow faster brake pad engagement...givng me more immediate feedback and confidence

If you were actually interested in a scientific or engineering test of the effect of rotor thickness on braking...this is the LAST way you would do it. Experts generally start with tests under controlled conditions that evaluate something specific; in this case, for example, there seems to be a hypothesis that a thicker rotor will store more heat and therefore temperatures will climb more slowly under braking. Great! Put together a setup that puts the same braking force into rotors of different thicknesses, and measure the temperature over time with an IR thermometer or embedded thermocouple. You could add realistic amounts of airflow, if you like, but the key factor would be isolating the factor you are interested in and reducing or eliminating the effects of confounding variables/factors, and doing an objective measurement that tests your hypothesis. What does "MTB PhD" do? On-trail testing with every possible confounding factor included, with a sample size of two tests per rotor thickness (!). He concedes that there is a wear difference between the thin and thick rotors (oops!), but neglects all the complex factors in his psychology and technique that could produce different results. He also doesn't have any kind of objective way to evaluate differences, beyond the "feel" or how he behaviorally braked. Did heat storage affect the effectiveness of his brakes? He literally can't tell you. Real-world testing only works when you have a large enough sample to isolate the variable you're interested in from all those other confounding factors. In this case you'd need both an objective measurement and likely tens of attempts from 40-50 different riders. Needless to say, this "test" isn't even close to the statistical power you'd need to make any kind of reliable conclusion. To be fair to "MTB Phd" he's hardly the only one putting meaningless tests out there as "science." Pretty much everything GCN labels as "science" suffers from the same flaws and is just as meaningless. You would just hope that somebody who sold themselves with research credentials would not jettison everything they learned doing that research when they started recording for RU-vid. And "with REAL Proof"? That's just clickbait snake oil.

My experience with new rotors of any thickness is similar to yours. The surface finish on new rotors are very abrasive. Machinists have gauges to measure this “roughness” in finish, and can grind the finish to various specifications. This surface will get smoother with use as the pads have various compositions that can be very abrasive. But all pads will wear away the surface finish eventually. The most grip is when they’re new and properly bed in. This is when you will have the most braking power regardless of rotor thickness.

man... I'm riding my 26" vintage winter bike and loving the cantilevers stopping power... I've ridden 29er hydro for over a decade and just randomly wanted a cheap bike... nah it's a sick bike. stops good.

I haven't come across a brake set that is better than my Hope V4's yet. Incredible power with great modulation is hard to beat, I did upgrade to the 223mm Galfer rotor upfront and a 220mm out back.

I work in automotive testing. I'm curious if you've ever experimented with DGPS systems such as OxTS or RaceLogic for any of your data collection. I suspect that signals from the IMUs involved would be too noisy to be useful with mountain biking, but I don't know of anybody who has actually tried it. Have you looked in to anything like that?

I purchased these rotors, 203 mm. Unfortunately, I was unable to install them in the SHIMANO DEORE M6120. The rotors were too thick. Colleagues, do you have any ideas on how they can be installed in this system?

On my touring bike I switched to Hope V4 Calipers with their 203mm vented discs front and rear with Dot 5 fluid and braking is so much better than with normal rotors and they run cooler.

Operating temperature also matters, to match the optimal ranges for the pads! Rider weight and trail style also has a large impact on use case for each set of brakes. And ergo considerations. I think 203 TRP 2.3mm rotors on 27.5” wheels is my winning choice. For a 29er, I’d consider going bigger.

How do you calculate braking force?

It is a pity you can't get thick rotors in a good variety of sizes and fitments. I used to use 2.3mm Tectro discs with Shimano XT brakes and the feel was great. I'm now using Sram code rsc and wanted to use 2.3mm discs but can't find them in 220 centerlock. The extra thickness would work wonders for spongy leavers and move the bight point further out from the grip.

I am just hobby mtber, but I am nerd so this channel is best find for long time =)

Can the zitto 2.3 rotor fit with sram db8 6 bolt?

I'm a little bit concerned about a possible scenario where my MT5 brakes get hotter with thicker 2.3 rotors due to a decrease in ventilation between pads and rotors. I've heard one bike mechanic blame Formula brakes for being too hot, exactly because of that. Do you think this might be a problem and a reason to stick with my stock 2.0 Magura rotors?

Found them!! Thanks. Let me know if you find 223mm or 246mm rotors for ebiking!!!

Bike industry says we need to buy more stuff again.

I’m gonna try it, my DH and e-bike both seem to have so much room I’m constantly resetting the pistons as the pad wear.

Nice one!!

How do i find what pads fit my bike? i have a ploygon siskiu t7 with tektro brakes and i am in due need for new pads, but i am not sure what to get? help me pls

Hey can you tell me how you found these rotors on Ali express? Me WANT!!!

I wish I had custom code RSCs that fit on the vented hope 3.3, I like sustained 100%+ steeps and heat management is a problem, fade or letting off = hospital. A wider braking surface would be better too, with wider pads, sometimes there's nothing left of my pads after a month. 99.99% of riders will never ride like that, so not enough demand for bigger brakes.

Have you tested or noticed a difference between DOT brake fluid brakes and mineral oil brakes.

I went the opposite way, I went from 203 front and rear sram centerline to 180 front 160 rear shimano slx, and I didn't notice any difference, I ride plenty of double blacks and they have more than enough power, the shimano rotors for sure have more bite than the sram ones though, I tried 180 centerline rotors and they weren't powerful enough, also the sram power organic pads have more bite than their quiet organic pads.

Post mount adapter for 246 ?

I have used the ZTTO heat dissipation rotors before, not sure of the thickness, but they are on par with shimano's Icetech rotors and suprior to SRAM centerline rotors. Will be checking the 2.3mm thick ones from them when its time to by new rotors.

I sometimes wonder how much a person who has completed a doctorate is going to help others working in a given field relating to it . Especially in smaller nations . I know a lady who completed a doctorate in the music field some years ago but hardly anyone has read or really benifitted from it .

Better make a research video if radiators on disc are more important than radiators on pads or vice versa.

interested to see what the cheapest brakes come out like

You can straighten thicker rotors more easily as well I have Shimano ice tech rotors from 2015, they are way too thin, the rear one is rubning but there's nothing we can really do about it, the mechanics at the shop have tried, you try to straighten it and it just ends up bending the other way and rubbing on the other side instead. Also rotor wear. Thicker ones will last longer before getting too thin for the brakes to actually work. Also even if your rotors

Mine is too thin my gf says. But I never had problems with my brakes. 😂

What are your top three websites then? Or your top 10 if you have that many? I like rim brakes. Work for me and easy to work on.

whoa i didn't know people use braking loggers

This rotor comparison topic is a very challenging one to explain .The biggest reason is the good number of stencillings and patterns used by one manufacturer over the years as well as the huge number of brands and overall design variations . I have about 80 styles in stock . Testing is possibly a nightmare . Some rotors in a given brand and size mostly have a pattern variation between sizes , I found .

For the sake of learning to be a better rider, and simple curiosity, I’d like to find a way to make observations like this on my e-bike. I am especially interested in the possibility of abs systems with large diameter thick rotors on MTB, both traditional and electric. Awesome video btw, I’m learning tons here.

Why not black rotors. The dark color will release more heat. Even where not contact with the pad, a painted surface will help radiate heat. Yes, the dark color will radiate more than the paint insulates.

Have you considered that the thicker rotors change the bite point and that’s why they felt the way they did. I feel like a lot of this is a placebo effect. New to new would be a better comparison but I still think the bite point is what you’re feeling the most.

Yup

5:18 I really don't like the MT5s, I had them on my bike and the modulation was awful. I was scared to go fast because they either wouldn't stop or flip me over. I tried everything and ended up swapping them to shimano brakes.

I have as I call, pornography of brakes: slx 7120 levers, mt520 calipers, zee finned brake pads and 2x ice tech 203mm rotors, best brakes I've had so far. On ebike with total riding mass 124kg, works very well.

💪🚴‍♂️👍

bigger on the front is a good idea just look at motorcycles 300mm on the front and 240mm on the rear as you brake the weight transfers to the front

That's a great topic, but the design of your experiment seems rather basic for a Ph.D. level scientist, as you mentioned yourself. It would be truly interesting to see measurable data on how it affects braking power, the amount of braking before fading, cooling down later, etc. Also, having proper control rotors, which are also new, would be valuable. Investigating the hardness of the ZTTO rotor, measured in HRC for example, and comparing it to branded ones could provide insights into its longevity in a long run.

i stopped the video at 3:16 when you said that there are people that didn't upgrade to bigger rotors because they think there is not enough ground clearance but they are ok with a dirt scraping 12 speed derailleur.... i know two S companies that make a lot of $ from these people...

I've switched to thicker rotors for some time and i didn't notice any difference in breaking performance whatsoever. So it only brings negatives being unsprung weight. As long as overheating is not an issue, thicker rotors will be an overall net negative.

Don't buy Chinese made Shimano disc rotors, why because that are only 1.7-1.6mm thick and the two sets I purchased from the bike shop were only 1.6mm. When I questioned the bike shop they had no answer, only to say that is what Shimano Australia supplied them. What's the problem, simple stamped on the disc is a warning to replace the rotors once the reach 1.5mm, so you only get 0.1mm of wear before they have to be replaced. The Japanese Shimano rotors are 1.9-1.8mm thick and they also are stamped and state they should be replaced when they reach 1.5mm thick. I have dumped Shimano and gone with 203mm Tektro rotors that measured 2.0mm thick and are also stamped to be replaced when they are 1.5mm thick. They were half the price of the Shimano Chinese made rotors. Now that I know there are such a thing as 2.3mm thick rotors I did consider buying some however a note of warning. I have read that they should be to be used with calipers that are designed for 2.3mm discs. With that additional cost it is not worth the added expense as I only do XC and any down hill sections are only short descents.

One more Ali express question: I find it difficult to find specific items. Have you found any 223mm or 246mm rotors or Ali express?

It amazes me that the bike industry is trying to recreate the wheel with brake size, thickness and power. As a former road racer and sport bike motorcyclist for nearly 30 years and mountain biker since the late 80’s, it’s well understood that better braking comes from larger and thicker rotors. Rotors that are drilled and float as well make substantial differences. The mix of steeper descents and faster speeds warrant larger thicker rotors 200mm and larger, where’s the average enduro, XC or trail bike will be best suited with no more than 203mm to 160mm rotors. It’s hard to take all this data collecting serious for something that is I’d say common knowledge in other communities. Anything over 200mm on a trail bike is overkill. Also, I’ll note that your info speaks nothing of the gyroscopic forces that come into play with rotors larger that 203mm.

Some caution should be advised I think. Some forks and frames can only go so big on rotor size and some calipers may not be compatible with the thick rotor trend also.

220 mph narration.

Do you really say innovative like that?

twenty years ? lol dude you dont look much older than 25. as to thicker rotors ? rubbish

End game is RIM BRAKES. The "Disc" is a whopping 698.5mm and 56mm WIDE with air cooling within the rotor. 🦾