Brake fade on longi...
 

[Closed] Brake fade on longish descent

 Pook
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Hi all,

I did the descent from Howtown to Harsop the other day, and about half way my brakes faded. The pads were fine, but the braking just felt a bit spongy. What causes this and how can i sort it?


 
Posted : 15/04/2009 9:42 am
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it is caused by the pads/fluid overheating.

You need to use the brakes less so that they dont heat up so much. try not to hold them permanently on as you are descending, just brake when you need it (easier said than done sometimes)


 
Posted : 15/04/2009 9:45 am
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and some brake models are better than others.

Also some brake pad materials/backing materials/rotor designs/piston materials are better at not transfering heat build up to the hydraulic fluid from the brake face.


 
Posted : 15/04/2009 9:47 am
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BB7 sorts it. Also use larger disks to aid heat dissipation.


 
Posted : 15/04/2009 9:47 am
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replace the fluid in your brakes... off-hand what brakeset are they, and when were they last serviced?


 
Posted : 15/04/2009 10:04 am
 Pook
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avid juicy 3 - not serviced in many moons. After a weekend in the Lakes I can't decide whether to upgrade forks or brakes....


 
Posted : 15/04/2009 10:38 am
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"The First Rule of Tuning" states that you should always upgrade your stopping power before you try to go any faster by upgrading your going power.

So:

Brakes
Then forks.

๐Ÿ™‚


 
Posted : 15/04/2009 10:49 am
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I had this problem and it was sorted by using resin pads and a bigger rotor up front. This is a much cheaper, and probably more effective, solution than upgrading your brakes.


 
Posted : 15/04/2009 10:50 am
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If the brakes have not been serviced in many moons then that is your answer - bleed thru with new fluid. It should be changed every year or two


 
Posted : 15/04/2009 10:51 am
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Using DOT 5.1 fluid as opposed to the DOT 4 fluid they come filled with would also help.


 
Posted : 15/04/2009 10:54 am
 Pook
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nice one - cheers all. Cracking riding in the Lakes though - there'll be a video coming up soon

;o)


 
Posted : 15/04/2009 12:03 pm
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The pads were fine, but the braking just felt a bit spongy
.

That's not what I'd term brake fade, with real brake fade the pads overheat and stop gripping the disc, the lever stays firm.
What you're describing is more likely to be caused by moisture in the brake fluid heating up turning into steam and causing the spongyness.
A change of fluid should sort it.


 
Posted : 15/04/2009 12:13 pm
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No need to change your brakes - Avid 3s should be well up to the task. Most likely problem, as has been said, is the old fluid. DOT fluid absorbs water, so needs changing every year or so.
Cannot think of anywhere in the UK where I have been worried about brake fade.


 
Posted : 15/04/2009 12:37 pm