Anyone ever had this before? Fitted new tyre over a week ago, pumped up to 120-ish psi, appeared perfectly seated on rim. Topped up with air tonight, drove to start of 10 mile time trial, checked everything at race HQ, rode 5 miles to start, *then* saw tube had got under bead and was pushing tyre off the rim.
It cost me a DNS because there wasn't time to let the air out, free the trapped tube and reinflate before my number was called. But why didn't the problem show up straight away, and only after a few miles of riding? The rims aren't damaged (splayed) in any way. They're the no-longer made Campag Omega V-shaped rims FWIW.
Zog The Undeniable <[email hidden]> wrote in message news:<409a9fb6.0@entanet>...
Quoted message said:
Anyone ever had this before? Fitted new tyre over a week ago, pumped up to 120-ish psi, appeared perfectly seated on rim. Topped up with air tonight, drove to start of 10 mile time trial, checked everything at race HQ, rode 5 miles to start, *then* saw tube had got under bead and was pushing tyre off the rim.
It cost me a DNS because there wasn't time to let the air out, free the trapped tube and reinflate before my number was called. But why didn't the problem show up straight away, and only after a few miles of riding? The rims aren't damaged (splayed) in any way. They're the no-longer made Campag Omega V-shaped rims FWIW.
Sure, lots of times. Then I learned to inflate the tube enough so that it would hold its shape while I put in in the tire and mounted the tire on the rim. As I get to pushing the last couple inches of bead onto the rim, I gradually let *just enough* air out to allow the bead to be squeezed to the center of the rim, leaving enough slack to complete mounting the tire.
Sure, lots of times. Then I learned to inflate the tube enough so that it would hold its shape while I put in in the tire and mounted the tire on the rim. As I get to pushing the last couple inches of bead onto the rim, I gradually let *just enough* air out to allow the bead to be squeezed to the center of the rim, leaving enough slack to complete mounting the tire.
Trust me, The Incredible Hulk couldn't do that with these tyres. They are unbelievably tight and the rims are very shallow. What I don't understand is why the problem didn't show up until I rode the bike.
Trust me, The Incredible Hulk couldn't do that with these tyres. They are unbelievably tight and the rims are very shallow. What I don't understand is why the problem didn't show up until I rode the bike.
Sometimes a tyre can take hours to blow off the rim if it's a poor fit. Your tyres might have been from a dodgy batch. Happened to me with *one* pair of Vittoria Open Corsas - on Open Pro rims. Inflate, wait, BANG!! ....Tested* twice more following the first accident, exactly the same thing happened, but not when fitted to MA2 rims. Other examples of the tyres have been fine on OP rims.
* If you suspect something's wrong, it's a good idea to inflate the tyre beyond usual pressure and leave standing for at least 24 hours to test it.
