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Be warned I am only posting this as it is slow today... I think I have a slow puncture, when there is no obvious nail / screw / whatever I tend to ask for an inner tube to be fitted as I feel that I would rather spend the £7 or whatever to get it fixed once as opposed to having to make several trips as the first fix did not work. Is there any schools of thought about a patch being better that a tube or visa versa with regards to performace / balance etc?
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The problem with fitting a tube is that you usually lose the self-sealing benefit of the tubeless tyre, i.e. when you get a nail in it, the tyre can deflate quite quickly, fast enough to be dangerous. I would definitely not fit a tube.
Could your pressure leakage be due to corrosion of the wheel on the tyre-seating face? This is not uncommon with alloy wheels in particular and the tyre depot will clean off the worst of the corrosion and reseal the tyre to the wheel (usually with a bright orange sealant that stains the hands and is very difficult to wash off!).
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I didn't know they'd fit a tube to a tubeless tyre these days. Wouldn't the old bath of water find the cause/source of the leak?
It's not the valve is it?
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Terry, I think you might be right - that tubes are now prohibited from being fitting in tubeless tyres. If not, it certainly ought to be so.
By the way, I don't know for sure why tubed tyres went flat so quickly, but that was the case.
When it was relatively common to fit a tube, a size intended for a cross-ply tyre was usually fitted because tubes weren't available in radial tyre sizes and aspect ratios, so you ended up with the wrong-sized tube. Another reason for not fitting a tube.
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Vern, you may have trouble getting anyone to fit an inner tube. Due to the litigeous nature these days, they won't do anything that could have the slightest effect on safety. Even if you sign a disclaimer, it still doesn't absolve them of blame.
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Well there you go, I shall turn up at mmy favorite tyre depot, present the problem and see what they suggest, and if they suggest a tube they will cease to be my favorite tyre depot. And there was me thinking this was a pointless post just to fill the space !!
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My understanding is that the main problem shows as the wheel rim profile the tube "sees". If you take an old car rim meant for tubed tyres the rim shape is quite a gentle curve.
More modern tubeless rims have a ledge/hump which is intended to stop the tyre falling into the rim well if it deflates.
The profile of this feature stretches the tube in a way it wasn't designed to and can lead to sudden failure.
So the "good old boy" who says I'll nip a tube in for you may not be right.
David W [Moderator]
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mailto:david_moderator@honestjohn.co.uk
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David
I'm not totally convinced rim profile is an issue with 'tubeless' rims. A tube is unlikely to be excessively stressed by that. Only if it significantly too small will there be problems, whatever the rim profile. More important is that When you fit a tube, then the valve to rim seal is lost, which is why a puncture is then more significant.
The more usual problem with fitting modern tubeless tyres on an old car with tube-type rims is that the rims themselves are probably not designed and manufactured to be air tight. The usual leak point is where the rim is rivetted to the wheel centre. In such cases a tube must be used. It would be more dangerous than to leave it out, even if the tyres are nominally tubeless.
This sort of leak may be the problem described here.
Regards
John S
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John,
I stand to be corrected on the "tube stretching over rim issue". It is just something I've heard ((many many years ago) and understood to be true, we'll have to get to the bottom of it!
David W [Moderator]
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mailto:david_moderator@honestjohn.co.uk
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My daughter's car has the same problem, loses at about 5 psi a month on one tyre.
I'll take it into our local reliable tyre dealers ASAP and get it checked out. I suspect that it is the valve. I have had a valve stem go, probably due to monkey-fisted fitting!
I wouldn't put a tube in a tubeless tyre, myself.
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Brian W
Have recently come across half a dozen valves where the leak was between the brass insert and the rubber moulding. All were original and none older than 3yrs. On a couple of them the insert could be easily pulled out with a pair of pliers - leaving the moulding in the rim. Instant deflation.
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This thread has just reminded me of my early motoring days - in 1960 with a 1937 Morris 8. I ran for many months with smooth treadless tyres until a balloon of red inner tube emerging through the very-visible canvas led to me buying a new set of remoulds (ugh!).
The thing was, I never got a puncture with the smooth tyres but had a regular blight of punctures with the new tyres because the treads picked up every nail and screw that I went anywhere near!
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Dizzy
And the slicks gave you maximum road contact in dry weather!
:o]
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