Fulcrum Racing 7 wheelset - sharp edge?

[goo_mason]

Bought a set of these two months ago for use as my 'summer' wheels, and finally fitted them last night as the weather's finally looking good for the whole week.

An hour after I'd finished, the back tyre suddenly went down with a mighty rush of air. Checked the tyre and the rim around the area where the tube was holed for anything sharp but couldn't feel anything. So, off came the wheel and I put on a brand new Schwalbe tube.

I pumped it up again but this time, just as it was reaching the ideal pressure, it burst with an almighty bang which blew the tyre off the rim! The hole was in a different place, so I checked the rim and tyre again for sharps - nothing. I suspect I may have pinched the tube slightly under the bead, though I always ensure that I check for this and have never had a tube explode on me in 7 years of fixing flats. So - I patched both tubes and put the original back in again, only for it to let go with another big rush of air 5 minutes later. I suspect the patch may have lifted, but it was so late that I couldn't be bothered taking the wheel off and getting the tube out yet again.

Seriously miffed, as I had to bus it in this morning on a beautiful day. I'll pop into the LBS on the way home tonight to buy a couple of new inner-tubes and perhaps some new rim-tape to replace the stuff that came on the wheels. I'll also give the wheel rims a damn good check tonight for any sharp edges as I've never this kind of problem with the previous 4 wheelsets.

Anyone got any other advice for potential causes that I should look out for?

 

[MrGrumpy]

I would make sure when fitting that you put a little bit air into the tubes and ensure that the tyre bead is fully seated in the rim. I have had issues quite recently where the tyre has popped out of the well of the rim due not being seated properly. Another thing is good rim tape and also check that the valve hole has no sharp edges. All of this is from my experience others may offer other advice?

 

[MrGrumpy]

Well.... I never has issues before about this but different rims and tyres can cause funny issues such as this. Just another thought, are the tyres blemish free ? Nothing sticking out of these ? Would not take much to to blow once the pressure is ramped up?

 

[goo_mason]

[QUOTE 2486991, member: 30090"]Agree with this. Pump the tyre up to 20 or so psi and then go around the tyre again making sure it is seated properly.

Having said that does seem a bit strange with regards to what has happened to the op.[/quote]

I always do that as standard - I inflate a little after fitting the tube / tyre and then go round the rim a few times manipulating the tyre back and forward to ensure it's properly-seated and nothing's pinched beneath the bead. (It was a trick I was taught on an Edinburgh Bike Coop Maintenance course 6 years ago).

Bought new rim tape last night and just fitted it over the existing tape - seems to have done the trick and there were no further unexpected deflation events, and I rode in the 10 miles to work without mishap this morning.

Thanks for the suggestions though, chaps!

 

[fossyant]

Talc the tube !