Overheating Disc Brakes

cycleclinic

When coming down the back of hardnot on a loaded bike i dragged the brake from top to bottom i had no choice it was that or crash. O. K i have a mechanical setup and steel rotors but the the rotors did not overheat. I use 160mm rotors and ebc pads.

The 160mm rotor rear is a very effective brake by itself. I like that. Bigger rotors help alot. Aluiminium carriers or shimano trick rotors help too. Finned pads help.

In short overheating can be avoided.

Moonbiker

Colwyd is long and crazy steep.

I bet its cooked alot of disc brakes.

https://www.strava.com/segments/7477402?filter=overall

ugo.santalucia

Moonbiker wrote:

Colwyd is long and crazy steep.

I bet its cooked alot of disc brakes.

https://www.strava.com/segments/7477402?filter=overall

I tend to agree... (while adding it to my secret To do list)

frisbee

Apparently although mineral oil isn't hygroscopic, water can still cause issues by collecting in a bubble in the hose and then boiling. Not entirely sure I believe the theory.

Bedding pads in properly makes a big difference. I don't really use my back brake, so light use and bit of contamination tends to glaze the pads. However if I clean it up and intentionally bed it in, it is far more powerful and needs almost no effort at the lever to lock the back wheel, the modulation is lovely as well.

on-yer-bike

Get rim brakes,

dinyull

SloppySchleckonds wrote:

Great thread "get dura ace" "get bigger rotors"

What rating are you giving it?

pedrospedros

Hi All
Problems with road bike overheating {smells like car clutch smell} and squealing especially in the rain,I used finned shimano and non finned, disc 160mm i do break them in , not sure what I am doing wrong
Regards

pedrospedros

Garmin 1000 edge Problems with the top of the screen, out of warranty starting fading

froze

I can't believe this, I actually got into an argument about disk brakes fading when they got hot at another forum and they all said no way would they do that...but here it is.

Rim brakes don't suffer as much from heat as disk brakes because the surface area is a lot larger with a rim then a disk, but if you have CF wheels or your bike is set up for disk then you don't have a choice, you have to use disk brakes.

You probably should look into larger diameter rotors if this hill it going to be something you'll do on a regular bases, the larger diameter rotor will dissipate heat quicker. The other thing you mentioned that you did but I want to find out how you did it was braking sharply and then releasing. What I did when I use to ride in mountainous areas was that I would hit the rear brake hard for about 5 seconds, then switch to the front brake releasing the rear, then alternate back and forth like that every 5 seconds, this gave enough time for my rims to begin the cooling process. Some will argue that slow and steady braking is better, problem with that is you're not allowing the disk or rim time to cool, and as the pads and disk gets hotter and hotter you'll have to apply more and more pressure. Try to recall a time when you saw trucks going down a long grade, those that were smoking their brakes at the end of the grade was because they were riding the brakes down, the proper way to slow a truck is to hit the brakes hard for about 5 seconds then release and let the truck roll back to the speed just before they hit the brakes and hit the brakes again hard, drivers that do this never smoke their brakes. This same thing works for bicycles.

The other think you can add to your braking is by setting upright in your seat so the wind catches your body.

pedrospedros

Good advice, thanks

N0bodyOfTheGoat

Moonbiker wrote:

Colwyd is long and crazy steep.

I bet its cooked alot of disc brakes.

https://www.strava.com/segments/7477402?filter=overall

Shock of the day, local hillclimb rider (a certain Mr Evans) has the anti-KOM! :shock:

Vino'sGhost

so im confused, i thought we all had to have disc brakes because they were safer than rim brakes etc etc modulation blah consistentblah , long descents blah, exploding innner tubes, delamination blah.

Turns out that really theyre heavier, not that good on steep or long descents, theres always the wet but to be honest in this summers thunderstorms most disc brake riders seem to adopt a state of fear and paralysis. Maybe they were riding with style and panache but they were so far behind i couldn't tell for sure.

imafatman

Get some decent rotors and pads.... Me and my bike last year were 150kg. I initially had problems but upgraded to the finned pads and the Ultegra "ice tech" Rotors. It got me down some pretty steep 900m descents, no fade, no drama.

I run 160mm discs but I would assume 140mms for normal sized riders would be more then adequate.

cycleclinic

The op needs bigger rotors. The op can try Shimano ice tech rotors. The op needs better pads, try ebc sintered for hill descents. There are solutions to these problems or we would have disc brakes on cars.

The fluild may not over heated but the pads can. I have overheated rim brake pads and the braking point got longer and longer. The pads were not the same after that ride.

Having ridden down hardknot dragging the brakes is essential.

timmyotool

thecycleclinic wrote:

The op needs bigger rotors. The op can try Shimano ice tech rotors. The op needs better pads, try ebc sintered for hill descents. There are solutions to these problems or we would have disc brakes on cars.

The fluild may not over heated but the pads can. I have overheated rim brake pads and the braking point got longer and longer. The pads were not the same after that ride.

Having ridden down hardknot dragging the brakes is essential.

Funny to see my post back in the news, while it's there, as I've made very little changes since then, it might be a good time to ask as I'm off to the Alps in a few months.

Which EBC are you referring to? Gold? It's hard to work out from their descriptions which suits.
https://ebcbrakes.com/articles/sintered ... ve-you-on/
would you recommend these over finned pads.
http://www.swissstop.ch/brakepads/discb ... /exotherm/

My current rotors are:
https://www.bike-discount.de/en/buy/shi ... ock-447127
Happy to spend the money to go to 160mm rotors but I still can't work out what adaptor is needed to get there for front or rear.
think it's this one but that only seems to be for front fork?
https://www.bike-discount.de/en/buy/shi ... 2000-25691

cycleclinic

I prefer the ebc pads over everything else. However Shimano do make sintered pad compounds with find. These are quite good. You may want to switch to the ultegtra or Dura ace rotors. The xt rotors are good enough most of the time but there is s reason why the road groups have the rotors they do, it's for those extreme descents that roadies love riding down.

cycleclinic

For adapters tektro can be cheaper.

If you have post mount fork with is mount calipers the you need the 160mm front/ 140mm rear adapter up front and the 180mm front/ 160mm rear up rear. And you do need 160mm rear whatever anyone tried and claims.

apreading

Shimano finned pads and ice-tec rotors are great. I have had none of the problems I had on really big descents on my last bike with Avid Elixirs since I got these. I have always been 160mm so never tried smaller. If you switch to a bigger rotor, check your forks and frame are rated for that size - some have a max of 140mm but most should be OK with 160mm. Not sure that road forks generally go any higher than that.

The finned rotors are only available for centre-lock I think, otherwise I would have those too as they look fab.