Inner tubes keep going pop

[Broadside]

A friend of mine has got a really weird problem with inner tubes going pop on the front wheel. He has a Mavic Aksium wheel with a Conti GP4000 tyre, the tyre is worn but not ridiculously so as it probably only has 1500 miles on it and up until this weekend had only ever punctured once or twice.

He keeps puncturing inner tubes every 5 or so miles, frequently less. The punctures are dramatic and all the air goes in about 2-3 secs. The tubes always puncture on the inside facing the rim and usually over a spoke hole so the first thing we did was whip off the rim tape, cleaned up and inspected for damage and sharp edges and then put some new Specialized rim tape on it, but the same thing still happens. it has happened over 3 different spoke holes so far. He has got through 5 tubes since Saturday, 3 Specialized tubes and 2 Decathlon.

I thought it might be some odd problem with the wheel flexing somehow, but this evening he has put the GP4000 tyre on a spare R500 wheel and the same thing has happened, so now it looks like the tyre is the culprit. Has anyone come across a problem like this? Is the carcass of the tyre somehow knackered and causing uneven pressure on the tube? I am at a bit of a loss to explain it. I am going to lend him a spare tyre to go on the Aksium wheel to see if that sorts it.

Does anyone have any ideas?

 

[steve52]

ah the home of the pu*******er fairy is discoverd? check spoke tention ? just an idear as one may be pushing through

 

[Broadside]

Good shout, but I checked that when the rim tape was off. On the Aksium front wheel the end of the spoke and nipple is below the rim wall that the inner tube sits on, probably about 5mm below it and all the spokes have a decent tension on them and don't appear to move about.

 

[PatrickPending]

I once ad a similar situation - couldn't figure out why I had a puncture every few km on a brand new tyre. After about the 6th puncture repair I changed the tyre, problem went away.

Always check for sharp objects still embedded in the tyre, the tube is properly seated and not catching, inflated to recommended pressure oh and you've checked the rim tape.....see what its like with a replacement tyre

 

[Broadside]

After about the 6th puncture repair I changed the tyre, problem went away.

Thanks, that makes me feel a bit better that someone else has had something similar happen that is impossible to understand! I agree, I think it is new tyre time. I am going to loan him a tyre to see what happens and if the problem goes away. It was gutting when it happened at the weekend as we were cycling from Fleet to Bristol and got within 5 miles of our target when he got these punctures in a row and we had to abandon the trip and phone my wife to rescue us!

 

[Shut Up Legs]

I had a similar issue with the tyre, and after 3 explosive tube punctures in 2 weeks, I replaced the tyre. But in my case, the tyre bead was defective, and so the tyre was actually unseating itself. From your description, I'm guessing that wasn't occurring?

 

[Banjo]

I went through a faze of this a while ago on my hybrid pub/work bike.In desperation chucked the wheel complete with tyre and tube in the shed and replaced it all. My son dug it out and has been using it for years without problem.

 

[Broadside]

So it seems like this is a weird problem, but not unique! I have given up trying to understand it so will see what happens when a different tyre goes on...

Thanks all.

 

[fossyant]

Have you given the tyre a good going over and checked if nothing is sticking through it. You've changed wheels, so it's not that. The thing that is constant is the tyre. All bets on the tyre being the cause.

 

[Broadside]

Thanks fossy, I have just checked the tyre thoroughly and found some splits in the carcass just above the bead. I only found this while pulling the tyre apart but it is clearly what has caused the last tube explosion.

Thanks for the pointer. The carcass has split in a couple of different places which is why the tubes were going at different points. That tyre is going in the bin now, not very impressed as you can still see the mould line on the centre of the tread so it is not a tyre with loads of mileage on it.