Will going tubeless eliminate heat related deflation?
I have tubeless ready carbon fiber rims on my rim-brake road bike. I've had two blow-outs while using tubes. Both happened after braking for a stop sign after descending a half mile hill of about 15% or more.
The rims are heating up and causing the tubes to fail. Do tubeless tires and sealant eliminate this risk? On long descents that are moderately steep. I alternate front and rear braking and can avoid a blowout. But on shorter steep hills stopping quickly is required. |
No, switching to tubeless will not prevent a heat-related blow off.
Heat does not cause tubes to fail. Heat causes tire blow offs. Heat:
What can you do?
|
Originally Posted by terrymorse
(Post 22782470)
No, switching to tubeless will not prevent a heat-related blow off.
Heat does not cause tubes to fail. Heat causes tire blow offs. Heat:
What can you do?
My disc-brake endurance bike just got the prime spot in the bike quiver and the rim brake road bike will only come out on perfectly flat routes. The Endurance bike was already the most versatile bike in the quiver, It's now the bike for any routes that aren't perfectly flat. |
Originally Posted by Barrettscv
(Post 22782381)
I have tubeless ready carbon fiber rims on my rim-brake road bike. I've had two blow-outs while using tubes. Both happened after braking for a stop sign after descending a half mile hill of about 15% or more.
The rims are heating up and causing the tubes to fail. Do tubeless tires and sealant eliminate this risk? On long descents that are moderately steep. I alternate front and rear braking and can avoid a blowout. But on shorter steep hills stopping quickly is required. |
Did you try thicker tubes?
It may be worth trying tubeless, especially if it's the tube that blows and not the tire. |
Originally Posted by eduskator
(Post 22782584)
It may be worth trying tubeless, especially if it's the tube that blows and not the tire.
|
Originally Posted by terrymorse
(Post 22782790)
Tubes don’t blow up or melt. The tire fails to hold the pressure, the tube escapes, boom!
|
Originally Posted by Trakhak
(Post 22782838)
Exactly. The tire already contains the total pressure of air in the tube (and is all that is keeping the tube from exploding). A "melted" tube would not alter the pressure inside the tire.
|
yikes - what brand/type rim and tire ?
|
I climb and descend quite a bit in Colorado and I've hit 57 mph, but I have no road conditions that require much braking. If the descent is winding, I brake briefly before each corner, if the turn radius requires it. The only road condition that might require extensive braking, is a rough or pot holed surface. I'd stay off that kind of road.
|
Are you absolutely certain its the tube failing from heat? What kind of tube is it? - Might be the tyre blowing off of the rim, causing the tube to blow out, or the tyre bead separating from heat.
Tubeless carbon rim .. the hookless kind of TL rim?! |
Originally Posted by phrantic09
(Post 22783151)
Regardless the bead rim interface on a TL or TLR tire is much stronger than a normal clincher
I’ve inspected the beads on tubed and tubeless versions of the same model tire. I saw nothing in the bead structure that would suggest a difference in blow off resistance. |
Originally Posted by terrymorse
(Post 22783302)
I doubt that. Do you have any references to support this claim that tubeless tire beads are stronger?
I’ve inspected the beads on tubes and tubeless tires of the same model tire. I saw nothing in the bead structure that would suggest a difference in blow off resistance. |
Originally Posted by terrymorse
(Post 22782790)
Tubes don’t blow up or melt. The tire fails to hold the pressure, the tube escapes, boom!
Originally Posted by terrymorse
(Post 22783302)
I doubt that. Do you have any references to support this claim that tubeless tire beads are stronger?
I’ve inspected the beads on tubed and tubeless versions of the same model tire. I saw nothing in the bead structure that would suggest a difference in blow off resistance. 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/ |
Originally Posted by chaadster
(Post 22783348)
Innertube manufacturers disagree with your assessment, and many warn about overheating the tube.
But a melted tube does not cause a sudden blow off (the subject of this thread). Blow offs are caused by the tire bead coming off the rim hook. If your tire goes "boom", it is not because your tube failed. |
Originally Posted by terrymorse
(Post 22783358)
Granted, tubes can soften at very high temperatures, leading to failures. Certain thermoplastic TPU tubes have low melting points, leading manufactures to "cover their backsides" warnings like "never use these tubes with rim brakes (triple-bang!)".
But a melted tube does not cause a sudden blow off (the subject of this thread). Blow offs are caused by the tire bead coming off the rim hook. If your tire goes "boom", it is not because your tube failed. |
Originally Posted by chaadster
(Post 22783369)
The OP clearly states “blow-outs,” not “blow-offs.”
If you hear a "boom", the tire came off the rim. |
Originally Posted by terrymorse
(Post 22783379)
Semantics. Two phrases that describe the same phenomenon, with the second one being more accurate.
If you hear a "boom", the tire came off the rim. The OP ought to relate whether the bead came off or not, and what the tube looked like. |
Also, is this a front tire phenomenon? If not, you're building up heat using the ineffective rear brake too much.
|
Originally Posted by terrymorse
(Post 22783379)
Semantics. Two phrases that describe the same phenomenon, with the second one being more accurate.
If you hear a "boom", the tire came off the rim. |
Originally Posted by Kontact
(Post 22783393)
Reading the OP, I can't tell if he's having blow offs. If the tube suddenly failed internally due just to melting, I don't see why you wouldn't get a popping noise as the pressure escaped out through the rim. Many would call that a "blow out".
The OP ought to relate whether the bead came off or not, and what the tube looked like. The common heat-induced failure mechanism is tire blow-off, caused by overpressure [EDIT: and the softening of the tire's bead]. It has been happening the same way, ever since cyclists with clincher tires started descending steep roads. Without exceeding the temperature limit of a butyl tube, an overpressure of 50% is possible, which is more than enough to blow a tire. Braking steadily for 30 seconds on a steep downhill will do the trick. |
Originally Posted by terrymorse
(Post 22783455)
People can hypothesize day and night ...
|
Agree. Absent more information from the OP none of us know what we are talking about .... :D How's that for a straight line?
|
Originally Posted by Barrettscv
(Post 22782381)
I have tubeless ready carbon fiber rims on my rim-brake road bike. I've had two blow-outs while using tubes. Both happened after braking for a stop sign after descending a half mile hill of about 15% or more.
The rims are heating up and causing the tubes to fail. Do tubeless tires and sealant eliminate this risk? On long descents that are moderately steep. I alternate front and rear braking and can avoid a blowout. But on shorter steep hills stopping quickly is required. (2) This is exactly why I insisted on getting hydraulic disc brakes. Those grades are prevalent where I live, and I am a bit paranoid on descents, and ride the brakes more than I rationally need to. If there was ever a compelling reason to get a new bike, it is this. |
Originally Posted by Kontact
(Post 22783395)
Also, is this a front tire phenomenon? If not, you're building up heat using the ineffective rear brake too much.
|
All times are GMT -6. The time now is 12:41 AM. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.