latex inner tubes with carbon rims?

on-yer-bike

Ive just seen this on the Michelin website: 'do not use latex inner tubes with carbon rims'. What is the reason for this?

drlodge

Probably a combination of carbon splinters and/or the rim getting hot. Latex is not as tough as butyl

cycleclinic

In reality under mormal conditions there is no issue. Put thousands of miles on my carbon wheels with latex tubes witn no issue. Gone tubeless now so no need for tubes anymore.

Remember campagnolo instructions say riding bike may lead to injury or death (i exgerate) so these things are oftem over done. They have to cover themselves.

ugo.santalucia

Carbon rims tend to get hotter than alloy rims upon braking, latex inner tubes don't like heat... they disintegrate fairly quickly if you heat them

sungod

^^^this

cf doesn't conduct heat as well as alloy, if the brake tracks get hot due to extreme conditions and/or bad technique then the inside rim wall can become hot enough to cause a latex tube to fail (even a butyl one if things get really bad)

some people manage to overheat their cf rims to the point the resin softens and the rim distorts, this is far above the temperature at which a latex tube will fail

alloy rims have much higher thermal conductivity, the rest of the rim acts as heatsink to help cool the brake track

cycleclinic

As i said under normal conditio it is not a problem. If you live in the mountians that changes matters most dont though. Most are not that lucky. Some get to live in the fens there i dont think overheating the rims will be an issue.

bomster

sungod wrote:

^^^this

cf doesn't conduct heat as well as alloy, if the brake tracks get hot due to extreme conditions and/or bad technique then the inside rim wall can become hot enough to cause a latex tube to fail (even a butyl one if things get really bad)

some people manage to overheat their cf rims to the point the resin softens and the rim distorts, this is far above the temperature at which a latex tube will fail

alloy rims have much higher thermal conductivity, the rest of the rim acts as heatsink to help cool the brake track

What is considered good technique for braking with carbon rims?

cycleclinic

Pulling the brake lever until you havd reduced your speed to what you want. People worry too much. If you worry about braking in carbon rims don't use them. Personally i don't worry and i would use the carbon clinchers i have anywhere in the u.k. there are a few decents in italy i have done i would not even dare use them as i know hot my alloy rims got.

stueys

Enve describe their logic well here. https://enve.zendesk.com/hc/en-us/artic ... her-Wheels

It's not about the heat tolerance, their view is that it's an inconsistent material to manufacture from.

ugo.santalucia

Stueys wrote:

Enve describe their logic well here. https://enve.zendesk.com/hc/en-us/artic ... her-Wheels

It's not about the heat tolerance, their view is that it's an inconsistent material to manufacture from.

I do agree with Enve statement... the thickness is totally inconsistent along the tube and the joint is a bit odd for something that is supposed to work in excess of 100 PSI.

However, specifically for carbon, it seems that latex is less heat resistant

cycleclinic

The problem is i have found no less and no more reliable than butyl tubes.

jefferson15109

Experiences with latex . Valve extender worked loose so flatted . Tightened then Inflated with Co2 at roadside . Got me home O K . Next morning , put normal air in but deflated quickly . It was a Vitoria 19/23 tube in a “ 25 “ tire which blows up to 27.5 on my 21mm internal rims . Did the extra stretching of the too small inner tube for the tyre compromise the structure of the latex ? Can’t think of any other reason as there was no puncture in the inner tube ( water bathed it ) !

daniel_b

I use latex with carbon rims with no issues - though I would not do so on a rim braked bike on an alpine descent, I don't have any of those near me.

This has been on both Mavic and Enve wheels.

I fitted my extenders with a healthy wrap around of ptfe tape, as that is meant to help things stay nice and snug - no issues yet.