Ajax Bay
Guru
- Location
- East Devon
Though this might cause a flat, the symptoms would not be "before setting out, only for it to still go "bang fsssssh" within 20 seconds."
Run of pinch flats and I don't know why
- Thread starter steverob
- Start date
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Gravity Aided
Legendary Member
- Location
- Land of Lincoln
Unless the imbedded object took a couple of turns of the wheel to break the tube. It may be less than obvious , hence the.cotton boll.
DRM
Guru
- Location
- West Yorks
I had a run of punctures this summer, it turned out to be the plastic rim tape that was fitted by the factory,pumping the tyre up to 80 ish psi would get me home, increasing the pressure to over 100 psi at home would mean coming back to a flat tyre the following day, being a bit OCD with regard to lining the tyre up with the valve/pressure range on the tyre meant being able to pin down where the fault was, which showed where the rim tape was moving away from the spoke holes under pressure, any way I fitted some velox cloth rim tape it's cured the problem, what you describe is what happened to me.
Ajax Bay
Guru
- Location
- East Devon
Lining up the logo on the tyre with the valve hole is not OCD, it's common sense, for exactly the reason you've described (as opposed to aesthetics).
What do you mean by "the rim tape was moving away from the spoke holes under pressure"? Why do you think the pressure 'moved' the rim tape? Was the rim tape still intact ie: didn't have any spoke hole diameter half circle cuts?
DRM
Guru
- Location
- West Yorks
Because, although the plastic rim tape was intact, it was sliding sideways under pressure, leaving part of the rims spoke holes exposed, I tried to line it up correctly but it just moved again, so I removed it, put it where it belonged (bin) and fitted the Velox self adhesive cloth tape, job done, I think others have removed the plastic rubbish that the manufacturers fit for similar reasons.
OP
OP
steverob
Guru
- Location
- Buckinghamshire
UPDATE - Due to family issues last weekend (and me being temporarily located over 150 miles from my bike), this afternoon has been the first chance I've had to take a look at my bike since first posting and I've now started to try and use you guys' expertise to help my diagnose the cause of my problems. I think I'm getting to the bottom of it now, but it's too late and too raining to go out on the bike to test it, so I'll have to wait until tomorrow to be 100% sure.
Just so you can see, here's a picture of the damage that was done to my inner tubes:
It may not be immediately clear from this photo, but there's actually two holes right next to each other there, but the second one hasn't completely cut a full circle out of the tube and the rubber has folded back over the hole.
Luckily I found the other two punctured tubes still in my garage (hadn't thrown them away as I thought) and was able to quickly verify that all three had similar holes and in the exact same location - at about 5 o'clock when the valve is at the top (or 7 o'clock, depending on which way you look at the wheel). Using that I was able to check the tyre in that location using cotton wool and found no foreign objects that might have been causing a puncture and also could not find any abnormalities in the rim tape by sight or feel.
However I did find a small cut in the tyre at about that location - it didn't look particularly big from the outside and I swear I've got at least two others elsewhere on the tyre that are about the same size. Below is a photo of said cut and considering I've tried stretching out the tyre for this picture to make it more visible, it still doesn't really stand out.
However, when I checked the inside of the tyre at this point, it did look a lot worse for than on the outside (unfortunately couldn't get a good photo of this). It still felt fairly smooth when running my finger over it (inside and out), but the cut looked a lot bigger on the inside. This suggests that the people on about a herniated inner tube poking through the tyre could possibly be on to something, especially if it only showed up when at higher pressures and when I had my full weight on the bike. Remember that my first puncture was fixed at the side of the road and I used a CO2 canister to inflate and this probably only gave me 60-70 psi, which was enough to get me 40 miles and home - the run of punctures only started when I emptied that and used my track pump to put me up to my usual 100psi.
So what I have done now is to swap the rear tyre from my spare bike to this bike - it's also a Gatorskin, although it is a 23mm instead of the 25mm I was running previously (and I still have a 25mm on the front wheel), changed the tube following all advice in this thread and have inflated it to 100psi. Wheeled the bike around the garage and it seems fine, but as I said, I haven't ridden it properly yet and won't until tomorrow, so watch this space.
Just so you can see, here's a picture of the damage that was done to my inner tubes:
It may not be immediately clear from this photo, but there's actually two holes right next to each other there, but the second one hasn't completely cut a full circle out of the tube and the rubber has folded back over the hole.
Luckily I found the other two punctured tubes still in my garage (hadn't thrown them away as I thought) and was able to quickly verify that all three had similar holes and in the exact same location - at about 5 o'clock when the valve is at the top (or 7 o'clock, depending on which way you look at the wheel). Using that I was able to check the tyre in that location using cotton wool and found no foreign objects that might have been causing a puncture and also could not find any abnormalities in the rim tape by sight or feel.
However I did find a small cut in the tyre at about that location - it didn't look particularly big from the outside and I swear I've got at least two others elsewhere on the tyre that are about the same size. Below is a photo of said cut and considering I've tried stretching out the tyre for this picture to make it more visible, it still doesn't really stand out.
However, when I checked the inside of the tyre at this point, it did look a lot worse for than on the outside (unfortunately couldn't get a good photo of this). It still felt fairly smooth when running my finger over it (inside and out), but the cut looked a lot bigger on the inside. This suggests that the people on about a herniated inner tube poking through the tyre could possibly be on to something, especially if it only showed up when at higher pressures and when I had my full weight on the bike. Remember that my first puncture was fixed at the side of the road and I used a CO2 canister to inflate and this probably only gave me 60-70 psi, which was enough to get me 40 miles and home - the run of punctures only started when I emptied that and used my track pump to put me up to my usual 100psi.
So what I have done now is to swap the rear tyre from my spare bike to this bike - it's also a Gatorskin, although it is a 23mm instead of the 25mm I was running previously (and I still have a 25mm on the front wheel), changed the tube following all advice in this thread and have inflated it to 100psi. Wheeled the bike around the garage and it seems fine, but as I said, I haven't ridden it properly yet and won't until tomorrow, so watch this space.
D
Deleted member 1258
Guest
If the damage inside the tyre is worse than on the outside Its likely that the tube was protruding into the cut and getting pinched.
iancity
Veteran
- Location
- Ashington, Northumberland
Been 3-4 weeks now Steve - how did it go?
