Dumb Puncture Question

badhorsy

I'm at my wits end.

In two days, I've had three punctures in the rear wheel. After every puncture, I've checked the tyre and replaced the inner tube.

The punctures are all particularly "slow" ones. I've only noticed them at the end of a given ride, by noticing a high pitched squeal. It takes hours for the tyre to fully deflate. I've checked the tyre inside and out for a small shard of something (they are Specialized Armadillo tyres though), but haven't found anything. All of the new inner tubes have suffered the same fate, so something must be causing it!

Any idea's? Or should I just check the tyre again, even more thoroughly this time...

mercurykev

I've had that before and it was cause by a tiny fleck of glass that was embedded in the tyre but was too small to poke through to the tube until the tire was inflated and ridden on. Very annoying. I'd suggest that you go round the outside of the tyre very slowly, flexing it to see if there are any small cuts and if there are investigating them closely to make sure that there isn't a tiny bit of glass hiding inside.

Lagavulin

Have you isolated where the punctures are coming from? Are they rim-side or tyre induced punctures. I only ask as having suffered a couple of punctures from running crap tyres on my first road bike, I then suffered a bout of punctures caused by the rubbish plastic rim tape supplied with the wheel set. Solved by Velox cloth tape.

Berk Bonebonce

Check outside of tyres with eye.
Check inside of tyre with eyes and fingers.
Check that spokes are not sticking through and puncturing tyre.

Surely where the puncture is occuring will give you a clue to what is causing the it/them.

markyone

badhorsy wrote:

I'm at my wits end.

In two days, I've had three punctures in the rear wheel. After every puncture, I've checked the tyre and replaced the inner tube.

The punctures are all particularly "slow" ones. I've only noticed them at the end of a given ride, by noticing a high pitched squeal. It takes hours for the tyre to fully deflate. I've checked the tyre inside and out for a small shard of something (they are Specialized Armadillo tyres though), but haven't found anything. All of the new inner tubes have suffered the same fate, so something must be causing it!

Any idea's? Or should I just check the tyre again, even more thoroughly this time...

hi i have put stans sealant in my road inner tubes and have not had a flat yet i even tested the tyres out by sticking small spike in tyre 3 times and its still not gone down.

Bobbinogs

I am assuming that you have definitely found a puncture before swapping/repairing, etc.? Is it a small hole and whereabouts on the tubes is the hole, same sort of position?

I would do what the chaps suggest and carefully check the tyre in bright light taking lots of time. Assuming you find nothing, if you suffer a puncture again then go with the "use the puncture to help you locate the problem" theme above. Carefully mark the tyre where the valve was with a piece of chalk before you take the tube off (or fit the tyre such that the label aligns) such that when you have found the puncture using water submersion, you can work out the area of the tyre affected.

If you cannot solve it, why not swap the tyres front and back and see if the problem moves with the tyre.

When I have had this problem, it was a very small shard of metal that could only be seen when folding the tyre back on itself. Happy hunting!

danowat

I've had this, turned out my rim tape was slightly off centre, allowing the spoke hole sharp edges to puncture the tube

sungod

i had this once, it turned out to be a piece of fine wire embedded the tyre, it was not visible and couldn't feel it, i think it only poked out when under pressure and weight on the tyre

as the others say, locate the position of the puncture with respect to the tyre and rim

i'm guessing you don't align the tyre to be in the same position on the rim every time, so if the holes are always the same distance from the valve, it's probably the rim/tape

if the holes are at varying distances, it's probably the tyre

next time, take care to note position of tyre vs. tube

to make it easier to check the tyre, wipe it clean/dry, then use a needle or pick to investigate every slight blemish on the surface and see if there's something inside

HadronCyclist

I've had a similar problem..three punctures on one ride though. To be honest, it could just be that the first one was bad luck, the second one was because of a pinch puncture caused by trapping the tube between the rim and tyre bead, and the final one was also just down to bad luck. or any combination.

Continuing the theme of identifying where the tube is puncturing, follow the advice of previous posts, but also make sure you are inflating the tube slightly before replacing it, and ensuring you aren't trapping it ready to get a pinch puncture.

Also try examining the tyre for any signs of a tiny tear. I know its tempting to just look for a shard of glass or metal, but it could just be that there is a very, very small tear that is trapping the tube and causing a point of increased friction, which could lead to a slow puncture like you described. If it is a small tear, just stick a repair patch over it and carry on. Simples.