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Latex corrosion

Zen Cyclery said:
I have heard a slight bit of buzz from random mechanics that latex will slightly corrode the carbon but I have never actually seen any evidence to back this up. I dont know if they were BSing me or not but you should be just fine.
Knowing both the chemistyr of latex rubber, and the chemistry of carbon fiber epoxy composites, plus the fact that the composite is covered with a clear coat, I have a VERY hard time thinking this is anything other than an urban myth. I would suggest that those mechanics really are random, very random.
 

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nicensleazy said:
I just thought latex inner tubes were more sensitive to heat than common tubes. So it could be, in case of overheating the rim?
Nope. Ridden mine in the mountains several times and never even worried about any sort of overheating.

Pros don't worry about it, why should you? They ride carbon tubulars with latex tubes sew-in.
 

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nicensleazy said:
I just thought latex inner tubes were more sensitive to heat than common tubes. So it could be, in case of overheating the rim?
From what I could find latex is good to ~ 140 F and butyl is good to ~ 250 F. Not really sure what "good" means but those temperatures were found in a few differenct sources. When I do my tire tests on PVC rollers which don't conduct heat very well the max temperature rise is ~ 40 F - I'd esimate that would be ~ 10 F on a flat surface. Not sure what temperatures might be experienced when braking for extended periods of time but apparently temperatures can get hot enough to soften tubular glue. The latex tube in a clincher wheel is in direct contact with the rim while the latex tube in a tubular tire is separated by the glue layer, base tape, and casing. This might be something to consider if you are thinking about the use of latex tubes in clincher tires when riding a course with some long and technical decents on a hot day ??
 

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3 years + no issues. Go for it. Make sure your rim tape is in good shape though. Some OEM rim strips suck.
 

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Jesus people, Coolhand and I have just said that we've had no issues. I'd be more worried about the fact that $3000 wheels have a 116psi limit...

I have an acquantance who rides his Reynolds DV46c wheels EVERYWHERE with zero issues.

Unless you are just LEANING on the brakes for extended periods of time, any heat created will quickly dissipate due to the air flowing over the rim surface. We're not talking about carbon rotors glowing orange here folks!
 

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Discussion Starter · #12 ·
backinthesaddle said:
Jesus people, Coolhand and I have just said that we've had no issues. I'd be more worried about the fact that $3000 wheels have a 116psi limit...

I have an acquantance who rides his Reynolds DV46c wheels EVERYWHERE with zero issues.

Unless you are just LEANING on the brakes for extended periods of time, any heat created will quickly dissipate due to the air flowing over the rim surface. We're not talking about carbon rotors glowing orange here folks!


Nicely put !
 

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Say what?

dadoflam said:
I just got a set of Lightweight clinchers - rim stickers highlight two conditions of use - max tire pressure 116llbs and No latex tubes. No reasons given but I understand it is related to the affect of heat
I can't imagine what possible reason they could give for not "allowing" latex tubes!

As to heat buildup, I have descended a mountain pass (US-14, west side of the Bighorn Mountains, 22 miles/35 km) and my rims were very hot to the touch. I'm guessing in the range of 140F/60C. Whether this would be a problem for latex tubes, I don't know.
 

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Kerry Irons said:
I can't imagine what possible reason they could give for not "allowing" latex tubes!

As to heat buildup, I have descended a mountain pass (US-14, west side of the Bighorn Mountains, 22 miles/35 km) and my rims were very hot to the touch. I'm guessing in the range of 140F/60C. Whether this would be a problem for latex tubes, I don't know.
But yet you posted....:rolleyes:
 

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Discussion Starter · #15 ·
An interesting twist. I spoke with Carbon Sports today in Germany. They stated, do NOT run latex inner tubes in their full carbon clincher. Apparently becuase of the heat build up, the latex is more prone to a blow out. This was found out whilst extensive tests were conducted! So, now looking for a good light weight butyl inner tube. I was thinking Continental Race Light 28. Any suggestions folks?
 

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backinthesaddle said:
Jesus people, Coolhand and I have just said that we've had no issues. I'd be more worried about the fact that $3000 wheels have a 116psi limit...

I have an acquantance who rides his Reynolds DV46c wheels EVERYWHERE with zero issues.

Unless you are just LEANING on the brakes for extended periods of time, any heat created will quickly dissipate due to the air flowing over the rim surface. We're not talking about carbon rotors glowing orange here folks!
you should google "anecdotal evidence." Glad to hear that your friend has no issues with his rims, but it takes more than n = 1 to make a valid inference about rim safety and heat. For one thing, you're wrong wrt heat dissipation being so rapid it does not have an effect on the rim. Rims typically heat in excess of 325 degrees during descents, enough to increase air pressure by 25 psi. That's enough to blow off a tire, and one reason why Zipp didn't make an all carbon clincher until recently - the numbers above are from Josh Poertner, Zipp's technical director. This sort of tire blowout happened on one of the rims discussed here in the latest carbon clincher review in Velonews.

You should also ask Reynolds how many delaminated rims they receive per year - you'd be surprised.
 

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FWIW, I think it was Michelin that stopped manufacturing latex tubes, though maybe Continental has too. There have been successful lawsuits against the manufacturers of latex tubes based on sudden blowouts and the allegation that the tubes are unsafe and prone to sudden blowout. As I understand it, the focus is upon the alleged strafe marks/scratches left on the surface of the tube from the manufacturing process on side of the tube where the seam is located (latex tubes all have an overlapped seam that butyl tubes do not). The manufacturers deny that these strafe marks are caused by the manufacturing process but they were settling the lawsuits for astronomical dollar figures rather than facing the prospect of letting a jury decide. I say all this second-hand and take it with a huge grain of salt. And on top of that, I happen to believe, FWLIW, that latex tubes are perfectly safe and that it is a shame that litigation has caused Michelin to decide that it is not worth the exposure to continue manufacturing the tubes.
 
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