Blowout - please help me find the cause
Jamey
Posts: 2,152
I extended my ride home from work today because it was my last ride before the London-to-Brighton on Sunday (wanted to rest a couple of days before it as it'll be my longest ride to date) and I wanted to do some hill training.
Ten seconds into the first decent hill, the tube in my front tyre blew with an almighty bang.
I had changed it last night as the previous one was leaking air and I was having to top it up every day, which annoyed me so I put a new tube in.
I had a spare tube with me and replaced it fine. What I want help with is identifying the cause of the blowout. One section of the tyre had a very thin strip of rubber hanging off at the very bottom of the sidewall, where the beading is. And the tube had a long (probably four inches long) slit in the same place.
Right now you're probably all thinking the exact same thing I thought at the time - that the brakes were rubbing... But I've checked them thoroughly and they're not. The rubber pads hit the rim squarely and are not in contact with the tyre anywhere. The little metal pins that hold the brake pads into the housing are sticking up a bit but even with the brake lever squeezed as hard as possible they're still a good 3-4mm away from the tyre rubber.
And yet something must have caused that blowout.
Prior to the event, I had been going down the aforementioned hill with the brakes on, and the wheel did feel a little warm when I took it off but despite being steep, the hill is only a few hundred metres long so it really couldn't have been enough to heat the tube to exploding point.
Rim tape was all secure and doing its job.
I'm a bit puzzled and worried that it might do it again on the London-to-Brighton because I won't be able to do a decent-length ride between now and Sunday. The tube that blew up (which I installed last night) still managed just over thirty miles before it went bang, so really I should test this one for at least that distance to see if whatever's causing the problem still exists, but I don't have that option.
The bike will be going to the shop tomorrow for the front wheel to be trued. Is there anything else you'd recommend I have them do at the same time?
Thanks for reading this far. I know it's a longwinded description but I thought it was better to give a full account of what happened.
Ten seconds into the first decent hill, the tube in my front tyre blew with an almighty bang.
I had changed it last night as the previous one was leaking air and I was having to top it up every day, which annoyed me so I put a new tube in.
I had a spare tube with me and replaced it fine. What I want help with is identifying the cause of the blowout. One section of the tyre had a very thin strip of rubber hanging off at the very bottom of the sidewall, where the beading is. And the tube had a long (probably four inches long) slit in the same place.
Right now you're probably all thinking the exact same thing I thought at the time - that the brakes were rubbing... But I've checked them thoroughly and they're not. The rubber pads hit the rim squarely and are not in contact with the tyre anywhere. The little metal pins that hold the brake pads into the housing are sticking up a bit but even with the brake lever squeezed as hard as possible they're still a good 3-4mm away from the tyre rubber.
And yet something must have caused that blowout.
Prior to the event, I had been going down the aforementioned hill with the brakes on, and the wheel did feel a little warm when I took it off but despite being steep, the hill is only a few hundred metres long so it really couldn't have been enough to heat the tube to exploding point.
Rim tape was all secure and doing its job.
I'm a bit puzzled and worried that it might do it again on the London-to-Brighton because I won't be able to do a decent-length ride between now and Sunday. The tube that blew up (which I installed last night) still managed just over thirty miles before it went bang, so really I should test this one for at least that distance to see if whatever's causing the problem still exists, but I don't have that option.
The bike will be going to the shop tomorrow for the front wheel to be trued. Is there anything else you'd recommend I have them do at the same time?
Thanks for reading this far. I know it's a longwinded description but I thought it was better to give a full account of what happened.
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Comments
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You've almost certainly trapped the tube between the tyre bead and rim as it's been fitted. Easily done, I've managed it myself on more than a handful of occasions.0
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Thank you. Any tips on how to avoid it in future?0
