# cork brake pads?



## CFBlue (Jun 28, 1999)

Anyone know the characteristics of cork brake pads? Is the purpose to withstand higher heat without melting, compared to rubber? 

I have a set of Corima cork pads that I originally got for some Velomax Ascent Pro carbon wheels. The pads, combined with the uncoated (no ceramic) rims worked like total crap.

Anyone use cork pads on aluminum rims (like Open Pros)? I'm thinking that for the rear, where you don't really need or want strong braking, using cork as a sort of "drag brake" down long descents (fixed gear) might be ideal, if the properties of cork lend themselves to sustained braking, but not necessarily strong braking. Any ideas? Thanks.

Doug


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## charlieboy (Sep 10, 2003)

*smoking re cork pads*

I thought for one moment this was a DIY method of recycling old champagne corks.

Picked this up somewhere

..formulated pads with cork for carbon rims, but this only serves to lower brake temperatures through low coefficient of friction, and therefore poor braking performance and feel...

I guess carbon rims heat up quicker than alloy with any type of brake material, and as cork grips worse it heats up less.

Why would you want to have some dodgy blocks on your bike - isn't it better to avoid lock up by feel and know you've got some bite back there if you need it?


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## spookyload (Jan 30, 2004)

I used to have some modolo brakes in the 80's that had their coposite brake pad that had cork in it. They didn't work as good as the Dura Ace brake pads I replaced them with. The really down side them was the smell. Yes, the smell. If you were in a hilly course and on the brakes a lot at high speed, they did heat up and smelled like a campfire blowing smoke in your face!


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## Spiderman (Feb 3, 2004)

Doug-
This is off topic, I know you are getting ready for the Fixed 508 and worried about heating up the rims too much. What about riding deep dish wheels which will sort of act as a heat sink and dissipate the heat. Is that a possibility?


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## CFBlue (Jun 28, 1999)

*rules*



 Spiderman said:


> Doug-
> This is off topic, I know you are getting ready for the Fixed 508 and worried about heating up the rims too much. What about riding deep dish wheels which will sort of act as a heat sink and dissipate the heat. Is that a possibility?


The rules, designed with a "classic" or "retro" aspect to them, limit rim depth to 25 mm with 32 spokes minimum. Could get a little deeper, but then they'd be heavier, too, and I'm looking for as little weight to haul up 35,000 feet of climbing with a 65 inch gear.

The rules:

F. Fixed Gear - Classic Division: Bikes must use the same fixed gearing (ring/cog) for the entire event. Bike frames shall be steel, traditional double diamond design (forks are unrestricted) and wheels (maximum 25 mm rim depth) with 32 spokes minimum. Aerobar/Spinaci attachments and aero-designed parts are prohibited. Wheel switches are permitted only for wheel failures, and must be identical or essentially identical to the failed wheel. Bike switches are not permitted. Riders may not coast with feet off the pedals. Riders must declare their gear (ring/cog) choice at check in, which may not be changed thereafter.

Fixed gear division riders may abandon that division and switch to a multispeed bike in the "open" division, then complete the race on the multispeed bike, provided that they or their crew notifies an official as soon as possible; they will then be treated as having ridden the event up to that point on the multispeed bike.

http://the508.com/intelligence/rules.html





Thanks.


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## Spiderman (Feb 3, 2004)

Hmm, well no way around that is there. I'll keep on mulling it over and see if anything else comes up.

Are drums brakes allowed? Or disc brakes (not very retro/traditional but maybe you could get away with it on a technicality)


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## JimP (Dec 18, 2001)

charlieboy said:


> I guess carbon rims heat up quicker than alloy with any type of brake material, and as cork grips worse it heats up less.


Charlie,

The issue is that the carbon rims do not accept or dissipate the heat from the pads. The pads actually melt and leave deposits on the rim. The cork impregnated pads work better on the carbon rims and have a much better feel than the non-cork pads.

Jim


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## charlieboy (Sep 10, 2003)

*I stand corrected*



JimP said:


> Charlie,
> 
> The issue is that the carbon rims do not accept or dissipate the heat from the pads. The pads actually melt and leave deposits on the rim. The cork impregnated pads work better on the carbon rims and have a much better feel than the non-cork pads.
> 
> Jim


Thanks Jim, there's another reason why I can't 'afford' carbon-rimmed wheels!!


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## jw25 (Feb 23, 2004)

DougSloan said:


> Anyone know the characteristics of cork brake pads? Is the purpose to withstand higher heat without melting, compared to rubber?
> 
> I have a set of Corima cork pads that I originally got for some Velomax Ascent Pro carbon wheels. The pads, combined with the uncoated (no ceramic) rims worked like total crap.
> 
> ...


Well, it looks like the cork issue has been discussed enough, so I'll only add the new Koolstop/Zipp carbon/carbon pads. They're made more like a "normal" pad, but will conduct heat from the rim to the caliper better than a standard pad. Supposed to be great on aluminum rims, too, and should slow rim heating as the caliper is a fairly large heat sink. I'm 99% sure the Koolstop pads are the same as the Zipp's, just less $. I know both are made by KS, but the KS package doesn't specify the additives.

Anywho, for less powerful braking, why not use a single-pivot sidepull? From what I've read, they don't apply as much force to the rim per increment of lever pull. Of course, they're lighter, too, so wouldn't have as much thermal mass.


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## Pierre (Jan 29, 2004)

*mmm... those rules are more like a guideline !*

Ask Chris Kostman about deep dish stuff, I bet this is not really forbidden. "no aero designed parts" ??? I know for a fact that a team was using disk wheels this year. The guy riding it told me he gained 1mph with it. 

And 32 spokes ? I bet not even half of the racers had that. Specially now that everybody likes to ride on the Ksyriums. Should have checked on that, it would have kept me occupied 

Pierre


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## CFBlue (Jun 28, 1999)

*not following*



Pierre said:


> Ask Chris Kostman about deep dish stuff, I bet this is not really forbidden. "no aero designed parts" ??? I know for a fact that a team was using disk wheels this year. The guy riding it told me he gained 1mph with it.
> 
> And 32 spokes ? I bet not even half of the racers had that. Specially now that everybody likes to ride on the Ksyriums. Should have checked on that, it would have kept me occupied
> 
> Pierre


Rim depth is limited to 25mm - not deep. 

I used a Cervelo P3 with disc and 404 up front in the team, and some aero parts in the solo, too. These are different rules, though.


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## Pierre (Jan 29, 2004)

*oh sorry*

didn't see this was for a special fixed gear category. Some crazy people have already done the 508 on a fixed gear ??? Well, actually why not, Kirsipuu did PBP on a scooter, so anything is possible.

Pierre


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## spookyload (Jan 30, 2004)

Man this thread was hijacked in a serious way.


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