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Carbon clincher failure - climb pictures
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If you're ever on the 81 corridor in the mid-atlantic region, stop in Harrisonburg, VA.


There is a great climb there called Reddish Knob that is not only gorgeous, but a ton of fun! (also the turn around of the Grindstone 100).

http://www.mapmyride.com/routes/view/36608532


I took to this climb last Friday while I was passing through.

It starts out nice and flat as you ride in.



First few miles aren't too steep. (the highest peak in the center of the frame is where you end up)




The day was a bit hazy and foggy in the valley, but eventually I got above most of the fog and clouds.



The avg grade is 6.3% I believe, but the first few miles bring down the avg of the last 3 which my Garmin was telling me was consistently 10-12%.



Pretty narrow towards the top. only wide enough for a bike and a car



Cresting the top (this would be an awesome finish to a race... that has only 15 riders. the top parking lot is pretty small!)



Amazing view at the top. If you're ever in the area, I highly recommend it!





The ridge in this picture is what you ride up.




So now my actual question: this descent is very windy and steep. I was riding carbon clinchers and was thus worried about overheating them whilst braking. For a descent like this (narrow, steep, windy) whats the best technique? Modulate? Take risks? Stay slow so you don't pick up too much speed?
Last edited by: %FTP: Sep 8, 11 8:11
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Re: Carbon clincher failure [%FTP] [ In reply to ]
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1st make sure you are on a good carbon clincher not a Gigantex or similar wheel out of china. the generic wheels use epoxys that have lower Tg and are more susceptable to failure.

Then do like the F1 drivers do. Brake hard and late. the less time you are contacting pad to rim the less heat accumulates and moves into the rim itself. Surface temps get very hot, but the heat pretty much stays there. Don't ride the brakes or temps will start to 'melt' the epoxy.

This is your life, and it's ending one minute at a time. - Fight Club
Industry Brat.
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Re: Carbon clincher failure [%FTP] [ In reply to ]
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at the top you will have gravitational potential energy defined by your height and you mass.

when you travel to the bottom all of that energy must be converted either to heat on your brakes and wheels, or the atmosphere from aerodynamic drag.

so you can go really fast and ralre touch the brakes and release all of that energy into the atmosphere

or go really slow, which puts almost all of the heat into the rim, but gives it plenty of time to dissipate into the atmosphere.

it would be the middle ground where you are going fast but riding the brakes for long periods of time that will overheat stuff.



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
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Re: Carbon clincher failure [Ti T'war] [ In reply to ]
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this was my strategy. hard quick braking. they didn't fail, so I guess it worked. but I probably wouldn't want to do it again just to be safe.
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Re: Carbon clincher failure [%FTP] [ In reply to ]
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No idea on the CC failure part BUT I went to JMU (Harrisonburg) and went to Reddish Knob a time or two---that would be a great ride BUT with that road make sure to watch out for the college kids!!
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Re: Carbon clincher failure [%FTP] [ In reply to ]
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Awesome climb!

We have a similar one here (~12.5 miles, ~6% grade) as well as some shorter (~3 miles) and steeper (~8-9%) climbs which I've ridden with carbon clinchers. I didn't have any issues, but my approach was to modulate less than I would with an aluminum rim (i.e. don't ride the brakes) and brake harder/later going into the turn to bleed speed. Not sure what you're riding, but I'm on a Reynolds Strike/Assault set. So far so good (knock on wood)!
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Re: Carbon clincher failure [%FTP] [ In reply to ]
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brakes only slow you down.
practice high speed cornering...
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Re: Carbon clincher failure [MCag512] [ In reply to ]
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riding the same. reynolds strikes.
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Re: Carbon clincher failure [jackmott] [ In reply to ]
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Quote:
have gravitational potential energy defined by your height and you mass.

HOWARD?!!!!
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Re: Carbon clincher failure [nickwhite] [ In reply to ]
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Brake hard before the corner and pick your line. Do not ride your brakes its the easiest way to overheat your rims. Carbon clinchers are dependent on the compound and brake pad you are using. But in general if you start to feel the brakes fade, just pull over. Its not like you're in a race.
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Re: Carbon clincher failure [nickwhite] [ In reply to ]
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The University of Massachusetts doesn't define gravitational potential energy?

Styrrell

Styrrell
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Re: Carbon clincher failure [styrrell] [ In reply to ]
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Boring but stop and let your brakes cool.
I dont know the grade here, but it is probably the safest bet. My rule is if I can't hold my fingers to the braking surface, then wait.

--
Patrick
Next up: GMSR and Bear Mtn Fall RR
Last edited by: pjcampbell: Sep 9, 11 11:06
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