Mineral Oil vs DOT, What Rotor Size Riders Need, and More Burning Questions Addressed - SRAM's Science of Stopping 27

The Science of Stopping is here to demystify the often misunderstood yet radically important world of mountain bike disc brakes and braking. We all have brakes, but do we know how to get the most out of them? By taking on topics such as the how and why of hydraulic disc brakes, while giving riders context to ride style, rotor size, fluid choice, and much more.
Related:
SRAM
Hydraulic Disc Brakes
27 comments

View replies to: Mineral Oil vs DOT, What Rotor Size Riders Need, and More Burning Questions Addressed - SRAM's Science of Stopping

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mtbboy1993
2 years ago
I've ridden - 11C never had issues with hydraulic brakes in sub zero temps. it would be interesting to see science about mineral oil, and different types, and dot fluid. and how safe or toxic they are. keep in mind brake fluid has antifreeze and some have colour agent in it. so it's not same as baby oil, which is mineral oil too. Only issues with seals i had were with faulty or worn out seals on Shimano brakes. but all seals wear eventually.
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eastenwreckoning543
2 years ago
Greg Minaar, the greatest downhill rider of all time, disagrees that DOT fluid is the best for performance applications.
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dreambikesonly
2 years ago
I've used a lot of 'dh brakes.' I weigh 215-230 lbs and ride at a high level on steep terrain as a preference. I've never met a brake that didn't fade. I have used 223 rotors for years and just ordered some Hayes. Galfer makes 246 ones, but man it would be nice if I didn't run out of brake all of the time. Interestingly, I don't think Codes are any better than TRP or Shimano in power or fade.
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dreambikesonly
2 years ago
That is 100% on my list. I figure if I already have everything else, some pricey brakes are well worth it. Just getting them is more my issue, but hoping that the DT buyout makes them more accessible.
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Will_Narayan
2 years ago
I'm surprised by the comment about rubber seals acting as a spring. I once removed the pistons from a caliper and it didn't look like those seals had much possibility to "stretch" to act this way.
I thought what brings the pistons back is the spring in the master cylinder sucking the fluid back up and consequently the pots coming as well.
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Erwan_Ghesquiere
2 years ago
Try and vaccum oil and all you will get is cavitation or low temp boiling by decrease of pressure. One sign of these seals getting tired is the reduced play between your pads and discs which usually cause constant rubbing has it is near impossible to center the caliper enough and have the disc straigth enough. Change those seals and problem is gone.
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Tmack
2 years ago
This is how car brakes work as well, square seals act as the spring. The master creating a c]vacuum on the return stroke merely acts as an aid more than anything.
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krisrayner
2 years ago
Good thing SRAM is doing their Level best to Guide us and de-Code the secrets of braking. That’s some Juicy info to gobble up.
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krisrayner
2 years ago
Lol, I wondered how long it would take...But in all seriousness I have a lot respect for engineers and the guys at SRAM, theres a local office in my town. But my personal experience has me going back to Shimano or Magura, just personal preference. The Avid/SRAM brakes that gave me the best reliability were old BB7's. Juicy's with horrible feel and reliability, Guides with their lever issues, my old Codes were finicky, my friends Levels with inconsistent bite...to each their own.
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TimBud
2 years ago
Conveniently missing out that there is not just one type of mineral oil. And that not all mineral oils are the same.
My opinion for Sram has sunk to a new low after watching this
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lister_yu
2 years ago
...and there is a mineral oil (TRICKSTUFF Bionol by Danico) that works up to 300 degrees celcius. It also has different viscosity compared to Magura and Shimano and in my opinion has a much better performance.
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mtbboy1993
2 years ago
great point, also they did not go into mechanical brakes much. this is just an ad masked as educational vid.
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Erwan_Ghesquiere
2 years ago
Yes it is very much but tbf I learned about disc discoloration. To me any color appearing was a bad sign of over heating, now I now that some color isn't a bad sign.
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Fred_Pop
2 years ago
Great video! It doesn't explain why Sram's only reasonable brake is the top of the line Code though. I'll be sticking to my "terrible" mineral oil Shimano Saints until I can afford some Trickstuff Maximas.
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BlazersDad89
2 years ago
That was great. Including the explanation of Shimanos variable bite point problem. That being said, Shimano, we look forward to your rebuttal.
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Erwan_Ghesquiere
2 years ago
BS explanation if you ask me. Otherwise swtiching to TRP lever would also show the problem of wandering bite point, or Tektro/TRP/Magura in general but these options don't give the damn wandering bite point. Shimano simply needs to fix their MC bore surface and stop with the shitty ceramic pistons. If they were listening there wouldn't be as many people switching to Magura or TRP, their lose really.
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Erwan_Ghesquiere
2 years ago
Let me help you fix that title : "SRAM's Science of Slowing you down, ... if you are lucky ... on a good day ...". There, you're welcome.
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