chaadster

Innertube manufacturers disagree with your assessment, and many warn about overheating the tube. There’s less fuss about it these days what with disc brakes n’ all, but Tubolito still indicate their S model is for disc only because of the heat issue.

Here’s a quote from Vittoria on the matter, from the VeloNews Technical FAQs column. It’s particular to latex, but also address the issues of butyl and heat generally:

“What is the heat tolerance of the average lightweight butyl tube and latex tube?
If the tube reaches the level of 100-140 degrees Celsius, all kinds of inner tubes will be destroyed.

And, how often do carbon clinchers reach temperatures that would lead a latex tube to fail?
This really depend on several factors, such as rim construction, -size, -resin and -tape. But mainly [it depends] on the end-user brake skills.

Agree that, “shorter, more powerful braking produces less heat buildup than does prolonged braking.” Similar to car brakes.

It’s not the tire bead, but the tube that cannot withstand the heat and give a sudden high pressure to tire bead. By the way, our tires run through a CQ that request 200 percent of the suggested maximum pressure. Example: Open CORSA CX 23mm 10.0 bar max tires have to withstand 20.0 bar at our derailing machine.

Is there another reason besides the heat issue that makes latex tubes unsafe for carbon clinchers?
Tubes are a rather sensitive product in general. Either Latex- or superlight Butyl tubes tend to explode suddenly, if not being used correctly. Some rules need to be followed:

1. Do not overheat the system
2. Do not lock the tube in between tire bead and rim hook
3. Prevent tube over-stretching in general — use recommended air pressure, rim tape and tube size
4. Prevent any sharp edges in the system
5. Prevent contamination with any oily substances”

— Christian Lademann
Product Manager, Vittoria S.p.A.

https://www.velonews.com/gear/techni...ubes-and-more/