The other day I read a question about heat induced brake fade in hydraulic disc brakes caused by too much braking on long, steep descents, which is something I have also experienced when cycling in the alps. (A quite unpleasant experience, I might add.) This made me wonder if mechanical disc brakes would suffer from the same problem. There is no fluid to start boiling, so at first thought they should be heat-fade-proof.

If so, I think an optimized disc brake system would have hydraulic activation of a short mechanical lever or wire connected to the caliper itself. This way the system would optimize modulation (by minimizing elasticity) while still being safe to brake for extended periods. I realize that even with mechanical brakes, you can't brake indefinitely, as the pads, calipers and discs would overheat at some point, but if the margin is large enough to cover most practical uses, the idea might be worth exploring.

So I'd like to hear from people with mechanical disc brakes if they have experienced heat induced fade?

  • 1
    All brakes can suffer from heat-induced fade. The failure mode of boiling fluid, however, is obviously only present with fluid-operated brakes. May 8 '15 at 11:50
  • Continuous braking is bad form. Do brake mostly front-end strongly for short patches of very good traction (no oil spills, no sand, no gravel) mostly prior to cornering or other dangerous situations.
    – Vorac
    Jul 12 '20 at 10:33

From my experience, the answer is no. I have been cycling across the Great Glen and have no problem with mechanical disc brake.

My bike was moderately loaded with camping equipment. So the load (including me 70 kg) was around 110 kg or 242 lbs. There were continuous downhill sections but the brake works fine, thankfully.

From a scientific stand-point, there are three types of fade

  1. Green fade - caused by resin boiling off of new pads
  2. Fluid fade - brake fluid boiling and system losing pressure
  3. Pad fade - pad overheats and loses friction

Ignoring 1, 3rd cause starts to occur at much higher temperature and require time than 2nd cause (which occurs at around 120 oC for moderately contaminated mineral oil*). That is why you need to check your mineral oil before setting out on a trip.

Pad fade is the main factor in Mechanical Disc brake fade. Unless you are not braking heavily and continuously for more than 10-20 minutes, you are fine. In number, if you are going down 20% gradient hill, braking continuously to keep your constant speed at 18 kmph (11 mph), the braking power is around 1078 Watts for 110 kg (bike+load+rider). That means, referring to **, you can safely brake for hours, if not hundred of hours for the iceTech.




  • Might be worth mentioning rotor size too = thick 180mm rotors will run cooler than thin road 140mm rotors.
    – Criggie
    Nov 12 '16 at 22:54

i recently had a problem with cable pull hydraulic assisted brakes system, i admit me and the bike weighs in at 120kgs and i was braking from 60 km/h on a steep slope, but i experienced nearly total brake failure . It was very scary , the calipers were making contact to the disc, but i was not slowing down, even using all my force in gripping the leavers it did not help. I guess i had boiled the brakes, the discs had changed color a bit and steamed when i added water, from my water bottle !! I imagine this is Brake fade at its most dangerous. I am now trying to go back to normal cable discs brakes. I wonder if rim brakes suffer from brake fad the way discs do =!?!?!

  • What does "cable pull hydraulic assisted" mean? Something like TRP Hy/RD? or like the Giant system with the reservoir on the stem? One or the other, once there is any "hydraulic" in the chain, it is not a pure mechanical disc brake and is prone to failure mode number 2 in the accepted answer.
    – Vladimir F
    Feb 24 '21 at 14:53
  • 3
    I think this does not actually answer the question. Please take the tour to see how to use this site and how to ask new questions.
    – Vladimir F
    Feb 24 '21 at 14:55
  • It sounds like you had everything hot enough to fade meachanical or hydraulic, or there's something else going on. Remember we have been using the same hydraulic fluids in car braking systems (and motorcycle) for a long time now and those brakes run much much hotter but also dissipate more heat.
    – JoeK
    Feb 24 '21 at 14:56

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