Blow-out - Michelin latex tube on SL23 rim

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Marin
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by Marin

If you are using tire levers to install a tire, you will almost certainly damage a latex tube.

If you are using tire levers to remove a tire and aren't super careful, you also have a pretty good chance to damage a latex tube.

Svetty
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by Svetty

WMW wrote:What did the hole look like? How big?


2-3 mm round, slightly ragged hole approx 1/3 of the way around the tube from the valve, on the side of the tube - neither opposite the rim tape nor tread. I'd estimate it would approximate to where the tyre abuts the bead hook. As I've said above, there is no damage or penetration site on the tyre. Of course I cannot be completely sure that a tiny sliver of tube wasn't interposed between the bead and the wheel but as there is no way to 100% check this after installation this still represents a potential hazard of using latex - many miles of safe use was not a reliable guide against this in my case IF this was the cause.

The fact that a number of wheel and tyre manufacturers have safety warnings advising against latex tubes does perhaps strengthen the anti-latex vibe I guess. Whether the fact that Conti don't manufacture a latex tube is relevant to their warnings regarding their use is open to question.....

I'm torn between trying again on the rear (don't feel I'd trust one on the front....), being even more careful (if that's possible) with installation or sticking with butyl. What is undeniable is that I had a sudden, rapid deflation with no apparent cause apart from possibly a rather warm rim.
Last edited by Svetty on Wed Jun 10, 2015 12:25 pm, edited 3 times in total.

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Svetty
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by Svetty

Marin wrote:If you are using tire levers to install a tire, you will almost certainly damage a latex tube.


Agree - that's why I never use levers to install tyres :D

Marin wrote:If you are using tire levers to remove a tire and aren't super careful, you also have a pretty good chance to damage a latex tube.


I remove tyres starting at the valve : my puncture wasn't near the valve so not relevant in my case but I agree this can be an issue with inexperienced operators.

mattr
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by mattr

spookyload wrote:You are saying the tire will shift on the rim under heavy braking? I call Shenanigans on that. The contact area of a tire on the rim has far too much friction for an inflated tire to do that. The only time that could possibly happen would be with a flat tire. Sure I have seen drag cars do that when they burn out, but you are honestly saying a bike tire will do that while inflated? BS.
What a delightful response, "my experience differs to yours, so you are lying".

sawyer
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by sawyer

bm0p700f wrote: Had blowout on butyl tubes though when the tyre gets cuts nevr had a latex tube blow out. They always leak more slowly. In book they are safer. .


Disagree that latex always leak more slowly - or rather that the rate at which latex tubes leak
makes them safer (presumably you mean in the case of a blow-out, rather than safer full stop?)

Both latex and butyl tubes can leak very quickly. That is why tubulars are safer. I actually think
the elasticity and the way latex tears may well mean they will often leak faster than a butyl tube
but certainly don't pretend that is any more than a hunch.

What is beyond doubt regardless of my experience or yours is that, given the relatively small number of people using latex tubes (vs butyl) there are a lot of reports of near instantaneous deflation on blow-out ...

@Svetty - sounds like you are very careful with installation and removal of tubes. I suggest trying tubulars and feeling good about railing down mountains knowing the chances of a blowout are next to zero (and enjoying the superior handling) ...
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WMW
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by WMW

Marin wrote:If you are using tire levers to install a tire, you will almost certainly damage a latex tube.

If you are using tire levers to remove a tire and aren't super careful, you also have a pretty good chance to damage a latex tube.


I use levers all the time and have never damaged the tubes.
formerly rruff...

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WMW
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by WMW

Svetty wrote:2-3 mm round, slightly ragged hole approx 1/3 of the way around the tube from the valve, on the side of the tube - neither opposite the rim tape nor tread. I'd estimate it would approximate to where the tyre abuts the bead hook.


Sounds like the tube was pinched. Yes, latex tubes can stay pinched for a long time before they fail.

Did you talc the tube and inside of the tire? Did you check for a pinched tube before inflating?
formerly rruff...

em3
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by em3

Svetty wrote:
The fact that a number of wheel and tyre manufacturers have safety warnings advising against latex tubes does perhaps strengthen the anti-latex vibe I guess. Whether the fact that Conti don't manufacture a latex tube is relevant to their warnings regarding their use is open to question.....



...the warning label prohibiting latex tubes on some rims is no different then lawyer tabs on ur forks....they exist ONLY because of potential user error, not manufacturing defects or weaknesses of the product.

In this case the puncture was likely user error (clearly sounds like a pinch flat) and has nothing to do with the robustness of the latex tube. Keep in mind that it is possible that u may have installed ur tube correctly and then when ur bike sat in garage and the latex tube deflated, the tube could have shifted....thus the reason any time u r inflating from scratch it is necessary to dbl check that the tube is fully inserted in the envelope. Lastly a heat related puncture is in almost all cases a full blowout of tube, not a piercing of the tube, like what occurred in this case.
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spookyload
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by spookyload

mattr wrote:
spookyload wrote:You are saying the tire will shift on the rim under heavy braking? I call Shenanigans on that. The contact area of a tire on the rim has far too much friction for an inflated tire to do that. The only time that could possibly happen would be with a flat tire. Sure I have seen drag cars do that when they burn out, but you are honestly saying a bike tire will do that while inflated? BS.
What a delightful response, "my experience differs to yours, so you are lying".

Your story simply defies physics. There is no way a tire will walk around the rim under heavy braking when inflated. Google the word "friction" and you will begin to understand how this isn't possible with the amount of force placed on the bead of the tire even the heaviest of braking will cause. We are talking about road tires at 100psi+, not a car with insane torque at the wheel. If this was a problem, you would see manufacturers using bead lockers to hold the tires. Instead, rim manufacturers are making beadless rims for mountain biking now. That is how unlikely what you are saying is.

Svetty
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by Svetty

Thanks to everyone who has contributed so far - the discussion is helpful. I suppose what is concerning me are the conditions under which the incident occurred e.g. the fact that it happened under heavy braking at speed when the rim was pretty warm.
Think I will give it another go on the rear as above. Perhaps then trying to duplicate the same conditions and see if I can provoke a recurrence. If I'm even more fastidious with fitting and I can induce a recurrence I can be assured that the issue is a consequence of the tube/rim/tyre combo rather then fitting.

@sawyer: with half a dozen wheel sets all clincher I'll need to invest in a set of tub compatible rims first ☺

sawyer
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by sawyer

em3 wrote:
Svetty wrote:
The fact that a number of wheel and tyre manufacturers have safety warnings advising against latex tubes does perhaps strengthen the anti-latex vibe I guess. Whether the fact that Conti don't manufacture a latex tube is relevant to their warnings regarding their use is open to question.....



...the warning label prohibiting latex tubes on some rims is no different then lawyer tabs on ur forks....they exist ONLY because of potential user error, not manufacturing defects or weaknesses of the product.
.


Reflects the risk of using them also mind you

I think we're all agreeing on this thread that it is very easy to make a mistake with a latex tube and that the results of such mistake may not be pretty
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WMW
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by WMW

sawyer wrote:I think we're all agreeing on this thread that it is very easy to make a mistake with a latex tube and that the results of such mistake may not be pretty


Precisely. It's also easy enough to avoid that risk by correct procedure.
formerly rruff...

sawyer
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by sawyer

WMW wrote:
sawyer wrote:I think we're all agreeing on this thread that it is very easy to make a mistake with a latex tube and that the results of such mistake may not be pretty


Precisely. It's also easy enough to avoid that risk by correct procedure.


Easy as you may find it to do it correctly, it appears many others find it just as easy to get it wrong! :wink:
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mattr
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by mattr

spookyload wrote:Your story simply defies physics. There is no way a tire will walk around the rim under heavy braking when inflated. Google the word "friction" and you will begin to understand how this isn't possible with the amount of force placed on the bead of the tire even the heaviest of braking will cause. We are talking about road tires at 100psi+, not a car with insane torque at the wheel. If this was a problem, you would see manufacturers using bead lockers to hold the tires. Instead, rim manufacturers are making beadless rims for mountain biking now. That is how unlikely what you are saying is.
I know what friction is and i also know that rims and tyres polish up over time. Reducing the coefficient of friction between tyre and rim. (i also know that MTB tyres move on the rim, and always have done, ripping valve stems off occurs fairly regularly even at 50+psi)

It's also not actually slip around the entire diameter.

Actually, f**k it, i don't even know why i'm bothering to explain, you've obviously made up your mind. :roll:

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Svetty
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by Svetty

OK, so have re-fitted tube with loads of talc. Double checked no tube under the beads and rim tape covering spokeholes and not folded/rucked. Valve properly seated. Have inflated to modest pressure, rechecked beads - all OK. Have then inflated to 140 PSI to see if could provoke any vulnerable sections to give way - nothing.
Have measured the inflated tyre - nominally size 23mm Ultremo ZX. Comes in at 26mm at widest point. Accordingly if I take this as the tyre size my rear pressure should be around 90 PSI. Seems slightly low but I'll try this and see how it goes.

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