does anyone have any idea how hot disc brakes can get, and if you ever suffered from brake failure? i 've seen ppl actually pour water on the brakes and massive amount of steam coming off but never know how hot it gets, any ideas?

wow you said steam did you well id say it would depend on the speed (of the ride)and tempreture of the day.

Next time ask him if you can touch it jks.

clipped

It wouldnt be the brake fluid boiling that causes the failure it would be the brake pads melting on the rotor. I have heard of that happening but have never personally seen it.

Not the temp. But I have seen burns into the skin like branding. Extended use of brakes causes overheating and then brake fade.

If brake fluid boils it causes condensation in the lines which contaminates the fluid, causes lines to rust from the inside out, and rubber hoses to wear out from the inside.

Not only does it boil hydraulic fluid, it causes air to go in, which could kill your brakes as you're going down a downhill descent. That can be dangerous. (No really) And if you're extreme, I would think getting these would help
1) Mech Discs
2) Bigger rotors.

I find this "glowing" disc brake thing hard to believe.

No offense hooligan but thats the dumbest thing I have read. Yes bigger rotors would help but mech brakes are worse. You loose signifigant power and increase strain on the hands (which means a couple of runs and your hands are fried) with cable actuated. You have just said the opposite of every dhiller and freeriders on the planet (no really...every one of them)

If you are loosing power because you have overheated a pre-bled system (where the bleed is fine)...here is a good option...don't use your brakes so much and learn how to modulate to allow them to cool. I promise you are overusing them if you suffer brake fade without REALLY long steep descents. (I am thinking like oasis in rossland which is excruciatingly long and very steep in section where it warrants laying on the brakes for extended periods).

I have never had my brakes overheat, disc or v. Even going down a 14mi descent riding a bike with v's I have never overheated my brakes.


I haven't seen anything like what you describe. Next time you see this could you try to get a pic.

[QUOTE=Maelstrom]Yes bigger rotors would help but mech brakes are worse.


Speaking of bigger rotors, could I adapt my shimano XT's to run 8" rotors, or would I need beefier hubs for that?

Cooling discs by sloshing water on them?! Surely the disc would warp and become unusable?

[QUOTE=six6one]Should be fine.

I've seen discs glowing red on cars and quads. Both had hydraulic systems.

I've wouldn't think on a steel rotor with not even 100kg of weight at 30mph tops you could cause a rotor to glow. F1 brakes glow as there carbon/ceramic?? they run hotter temps and the actual materials boiling point is lower. FIA GT cars run iron discs and never glow even though they can reach hundreds of degrees. As far as I know anyway...

I read too that to bed in the brakes properly you should do some hard stops then pour water over them to cool, then repeat. Supposed to do something to the surface?

I saw an Open University video from the '70s where they drove a Ford Escort upto only 40mph and braked it hard and the disc went orange hot...

Pouring water on really hot brakes is not a good idea. Im not sure why but in the motorcycle world if your brakes are hot and you go through a creek you lose your brakes for a good 5-10 minutes. I can find out hwy if someone really wants to know.

Where I live there are plenty of large hills that give my discs a nice workout. No problem with them fading from heat. Even in the rain the hold up well, better in fact. I can't say to date that I've seen the rotors glow red, orange or any other color. They are cheap Hayes mechanical disc brakes but they work great for me and never have to worry about over-heating anything like V brakes did with the rim and tube.

I've looked around and I read somewhere that disc brakes get somewhere around 300+ degrees. Don't touch it... Yes bigger rotors help as well as better ventilated calipers. (Hayes G2 come to mind) But on the longer steep runs, its not odd to see a glowing rotor.

"my friend went to panorama and everytime he went down the hill on crazy train the brakes woudl heat up so much that they wouldent work u have to spray down with water... he touched his brakes he burned his fingers lol .. they get pretty hot.. he has hayes hfx 9 and in all his biking he has never seen brakes glow red or orange i think ur kinda lieing there"

I didn't type that up, my friend did, thats why its in quotation marks. But I was suppose to say that my friend etc.. you get the idea.

From you last post I kinda figured you were a bc guy (or at least near enough) Still gotta hit up panorama sometime. Welcome to the forums.

Thanks, That was a friend of mine though that had wrote that, i just copied and pasted it from our msn convo, he went up there during the summer for biking, he met byron grey.

He wanted me to basically re-write it but I'm too lazy to do that.

Hahaha...no worries. Byron Grey is a pretty cool guy. Most of the bc riders arethoguh

The stinky is autographed by Byron Grey, same with his brothers Kona Stuff.

Well, then why won't dhers use 6'' rotors? Because they overheat! :S