A pair of schwalbe lugano 700 x 23c wire bead tyres, fitted on saturday. The rear one blew off the rim (massive bang!) when it had just been fitted (i was in the shed when it went-loud!) suspecting my poor fitting technique, i replaced the tube and went riding.
After half a mile, both tyres had started to unseat from the rim, with the tube starting to appear. I quickly let the tyres down and went home to check and reinflate. I did this but it happened again on the ride. I have since borrowed a pair of tyres which have been spot on. Should i send the tyres back (they only have 10 miles on them!)Tried at 6 and 7 bar (recommended min, 6 and max 7.5)
Is this a Schwalbe thing?
Maybe a rim thing, my Luganos are pretty tight to my Easton rims. Although I have folding tyres on mine. I had swapped the wire beads that came with the bike and they were fine also.
What's the rim? I had some Lugano 700x23 wires on a Shimano rim and they were fine. Well, they stayed on the rim well enough, their grip to the road however was woeful in the wet!
Are your inner tubes too big?
Just continental tubes, Race 28's wich i beleive will do 18 to 25 tyres. The wheels are some oem giant things. @cp, i've heard that to be the case, but not really had chance to ride them yet!
Hmmm, well 'Race 28's' sound like tubes for 28mm tyres and your running 23mm tyres? I've never had an issue when using oversized tubes but I suppose if your tyres are a bit under and your tubes a bit over that could be it...
I'd be more inclined to check your fitting and ensure there is no tube trapped below the bead before inflating. That's more than likely the problem particularly if your tubes are a bit big for your tyres.
Fair point, i'll check the conti site
Hmmm, states 18-25mm tyres.
Race 28 refers to the diameter
Hmmm, well 'Race 28's' sound like tubes for 28mm tyres
28 = 28 inch = 700c, race = 18-25. correct tubes.
Are you sure you seated them right?
Down to seating then...
You say about seating, but mates new Decathlon Triban 5 tyre blew off the rim after 2 miles. The tyre was so loose it was dangerous. Going to take it back, but in the meantime has bought the Luganos off Merlin and all is fine and proper fitting.
I've tried to inflate them slightly, roll them on the floor and check seating (tube trapped etc) then inflate up to pressure. They still go. I'm reluctant to try them again-i don't want a tyre to 'properly' blow while i'm JRA (just riding along)
If it was a rim such as a Stans Alpha then I would agree that it's easy to not get the tyre bead properly seated, as it needs to pop-up onto the shoulder, and the rim doesn't have such a large lip - sometimes some part of the bead stays down in the well leaving the bead opposite a bit loose.
However, with a standard type of rim I wouldn't see this as such a risk.
I have had some cheap MTB tyres which have been so loose that they've popped off without any provocation, which I chucked pronto. Certainly wouldn't want a road tyre popping off while JRA :O
Cheers, Rich
Check the rims very carefully before putting anything else on, and don't try those tyres again. Sometimes one poorly seated tire popping off can put a dent in the rim just from the force of the pop. Expensive mistake when I made it - new rim time, as even when I bent it back in it wouldn't brake properly.
If they both did it front and back, it probably isn't anything you did, it probably is them. Not worth risking rims messing around further.
Cool, thanks guys (off to call shop)
It does sound odd if they were seated properly (as in no inner tube trapped). I'd double check it (with about 20 psi in the tyre go around the whole rim on both sides pushing the sidewall in and checking you can see the rim bed and no inner tube is visible. I guess it could be some weird rim/tyre combo or a faulty rim/tyre bead but I've only ever had a tyre blow off when I fitted it in a hurry (or not been extra careful when using a latex tube) and trapped the tube. Although it normally blows off during the initial pump up I've also done a 15 mile test ride fine and then had it blow off the next morning when pumping it up ready for an event (it just so happened to be at 5am on a Sunday morning to, much to the neighbour's delight).
edit: Also don't screw down the valve lock nut too tightly, especially before it's properly inflated as this can pull the inner tube off the rim bed and interfere with the tyre seating at the valve area