Repeated inner tube punctures. Continental & Halfords. Mavic & Araya rims.

[Craigmount]

Hi folks, I hope someone can give me a few pointers on where I’m going wrong!
I’ve had say 12 to 15 punctures in the past 12 months, all on the rear wheel. Both Presta and Schrader valves. The punctures are always around where the valve metal sleeve meets the rubber tube. See pics 1 and 2.
The inner tubes are nothing special, a variety of what’s available locally e.g. Continental, Halfords, etc.

This all started last year when I bought a new Kenda folding bead tyre from Halfords, to replace a fixed bead tyre on my Cannondale (which has Mavic 117 rims).
This tube lasted 2 weeks, and so did the next, and the next ………………

The Cannondale developed a fork collapse, so I switched to the Stumpjumper!

This was fine to begin with, until I replaced the rear tyre with a pre-used folding bead IRC Mythos tyre.
And once again I had the repeating puncture problem, this time a Mavic 517 rim. See pic 3.

1. Inner tube size is usually up to 2.5 and the max tyre size on my bikes is 2.1
2. I switched the Kenda folding tyre to the “old faithful” Specialized Hardrock (Araya rims), and lo and behold: no punctures so far (see pic 4).
3. I always try to keep tyre pressures up, however I only have a hand pump, no foot pump.


What might be causing this regular (exasperating) routine? Is it the folding bead, or the rim, or the tyre pressures, or a combo, or anything else?
Any thoughts or comments wold be much appreciated.

 

[mk one]

Usually caused by the inner tube moving around the inside by the tyre under braking, also caused by a rough burr on the inside of the valve hole on the rim.

Check the valve hole on the rim for rough edges, if still happening some talc inside the tyre stops the tyre gripping the inner tube and dragging it round while braking.

 

[Tsundere]

There could be a tiny object embedded in the tyre, I had repeated punctures earlier this summer, three in about a month, after the third one I noticed how close to the same spot each puncture was in relation to the valve, it took me a while but I eventually found a tiny sliver of metal, no more than half the width of a small book staple and only a a few mm in length imbedded at an angle in the tyre casing, it wasn't even protruding under normal conditions, but I'm assuming that if a stone or other object struck the tyre at the right spot and with the right amount of force it would flex the tyre casing enough to expose the object and enable it to pierce the tube.

Since then I've had no punctures.

 

[Craigmount]

Thanks both, mk one and tsundere, much appreciated.
I’ll double-check the inside of the tyre, see if I can detect anything. I can also try the “talc” trick, and check for burrs.

My suspicion (although I’m not sure) is that the tyre is sliding round the rim (under braking or up a steep hill) and dragging the inner tube with it.
How do I stop the tyre sliding round the rim? Shouldn’t the tyre bead grip the inside of the rim, when inflated, and not move?
Is there any suspicion out there that folding-bead tyres grip the rim less well than non-folding? (haven’t had this issue with non-folding tyres).

 

[Baulz]

I went through the same problem as Tsundere years ago, there was a single strand of wire from a shifter or brake cable barely poking though the tire.

As another thing to check how loose the tire bead is on the rim, a loose fit may allow more movement then a tire that fits tight.

 

[Craigmount]

Thanks Baulz, yes I would say the tyre bead is looser on the rim than your average tyre. it’s a fairly tight fit, but I can usually get the tyre back on the rim without using levers.

 

[Tootyred]

Its unlikely you put the tyre back in the same position each time...as thats a random thing....unless you have to have the valve opposite the makers label....(stop it ocd...stop).

And as you say it happens with different tyres and rims....

Are you seating the tube when you start to pump it up? Ie. Put a bit of pressure in then push the valve back into the tyre.....then pump it up, then do up the valve retainer.......else, especially with a loose fit tyre, you could well be nipping the tube each time.

 

[Gtpulse]

It looks a lot like it is rupturing through the hole for the valve. I had this happen when using presta valves in shrader rims with a collar on the valve stem. Had 2 punctures on one ride in the same place as you. I solved it by cutting an old piece of tyre sidewall, punched a hole smaller than the valve in it and placed that over the valve hole inside the rim. It stopped the rubber bulging out.

 

[Craigmount]

Thanks Red. Methodical - yep. OCD - naw.
Both the Kenda and Mythos tyres feel a bit loose on the rim compared to what I’m used to with wired bead. However they both seem to seat properly on the rim when pumped up, with no “raised” spots.

 

[Craigmount]

It looks a lot like it is rupturing through the hole for the valve. I had this happen when using presta valves in shrader rims with a collar on the valve stem. Had 2 punctures on one ride in the same place as you. I solved it by cutting an old piece of tyre sidewall, punched a hole smaller than the valve in it and placed that over the valve hole inside the rim. It stopped the rubber bulging out.

Many thanks, I’m getting ruptures with both presta and schrader, however the schraders seem to last longer.
My last 2 ruptures were similar to yours, presta (with collars) in schrader holes. I’m going to try what you suggest and fit a tight membrane (from an old inner tube - plenty of them!) inside the tyre, fingers crossed the extra protection will save the day (and wallet). Thanks for the “heads-up”.