Rim/Tyre incompatability??

Gary D

Is there such a thing as an incompatibility between certain tyres and rims?

The reason I ask is that I have suffered 3 instantaneous deflations (blow outs!!) recently - 2 this weekend. One on the rear wheel yesterday and the other on the front wheel today. With all of them, I had no warning and then suddenly a bang like a rifle shot and then down on the rim. When I removed the tubes, they had split along the length for about 120-150mm. I had not ridden over a pothole, certainly not within 20 minutes or so, and was travelling at 16-18mph on a flat road. On each occasion, the tube had been in for a few weeks. I would have thought that if I had pinched the tube it would have gone sooner?

I am using the wheels that my Spesh Tricross was supplied with - Alex ACE-19 - and Schwalbe Marathon 28C tyres.
I spent the whole summer using Conti Gatorskins 25C (the narrowest I could fit according to Sheldon's formula) and never had any problems at all. The problems only started when I fitted the wider tyres for the winter.

My theory is that the tyre is somehow coming unseated from the rim and the tube is extruding itself out. Is this possible? I am a fairly heavy 16st :oops: , but I keep the tyres well inflated and checked them this morning to their max of 100psi.

The really scary thing about todays incident was that the tube blew out from the tyre and nearly wrapped itself around the brake calipers and even more frightening was that I had just come down a nice hill about 3 minutes prior and hit 40mph!! If the blowout had occured then I would have been highway pizza! :shock: :shock:

So, is it possible that some tyres are not compatible with some rims? Or is there a problem with Schwalbe Marathons? The tyres do seem to go on the rims very easily without levers. Or is it in fact, the idiot that is fitting them?

Sorry to go on, but I thought I would include as much detail as possible so you experts could point me in the right direction. I really need to get to bottom of this as I can do without any more brown trouser moments :?

Thanks, Gary.

rustychisel

Yes it is, Gary. You are correct. Generally we're talking about tyres being too large circumference (rather than the other way round, which can be an absolute bugger to mount).
I have had the same 'issues' with Continental tyres on some Asian rims (Araya, I recall, but I'd have to check).

Possibly also is the problem of hasty or incorrect tube and tyre installation... the tube pinched under the tyre bead or the bead not seated properly in the rim. But I have the same issue with a couple of wheels - one a 27inch which I dismantled because 27" tyres are rubbish and kept blowing out in exactly the way you describe.

Good luck, it's bloody annoying, isn't it. Oh yeah, and dangerous. [Send the buggers back]... but it's a hard case to make unless the bike shop know you and trust your judgement as well as their own.

scherrit

Yup,
This is one that drives bike mechanics to absolute distraction... and broken tyre levers. When the tolerances are just right, you can do a no-tools removal and re-fit of a tyre, and never have it blow off the rim. If these are not good, either you break levers trying to get tyres off or on (some 650 tyres and rims are spectacularly bad!) and the tyre won't seat in the hook, some of the beads stubbornly sits in the well, refusing to pop up even under track tubular pressure persuasion, OR the beads go pop letting a bubble of inner tube blow up in your face.... lovely and for extra effect try a slime filled tube!!!

I am pretty pig headed/stubborn but I have returned tyres that are essentially un-fit-able. Also, fine for me to wrestle in the workshop but pity the 50kg rider (with smaller, weaker hands than the workshop gorilla) who gets to wrestle IN THE RAIN AND DARK with the same punctured tyre....

Whoops, I accidentally raved there...
S.

Gary D

Thanks rustychisel & scherrit,

It's good to hear others have experienced similar problems.

I am pretty sure I hadn't pinched the tube when I put them on, as I partially inflate the tyre and check it both sides all the way around by pushing the tyre away from the rim to see if I can see the tube. On both recent occasions the tyres and tubes were fitted in my garage and not at the roadside - so it wasn't rushed.

I guess the only answer is to just buy a new set of different tyres?

Thanks,
Gary.

COVEC

I thought I would revive an older thread rather than start a new one,

I am thinking of getting some slightly racier tyres for my steed with the onset of Spring(please turn up soon Spring Bunny 8) ). I am trying to find out which tyres are generally the easiest to deal with by the roadside, with regard to removal and refitting in a puncture scenario.
Is any brand renowned for being easy to fit and which ones are to be avoided due to being very tough?
I hope that makes some sense

Cheers
COVEC

Gary D

I think that from the replies received on this thread, along with those from another recent similar one, it all depends on the tyre/rim combination.

Perhaps you should specify your current rim and what make and size of tyre you are thinking about?

I vaguely remember for example that some of the Campag wheels have problems with certain tyres? Maybe someone with experience could verify that?

I know that since putting my Conti Gatorskins back on, I haven't had any further problems, so I could recommend those tyres on the Alex ACE-19 rims. They are also very easy to remove and re-fit (without levers). That doesn't mean to say that someone else will reply to this thread and say what a mare gatorskins are to fit!! Therefore, the only conclusion I can come to is that it is down to tyre and rim compatability.

Hope this helps.
Gary.

cpeachey

I read some words by Chris Juden on this problem. He sugested that the standard for rims does not specify a deep enough well so some tyres will roll in the rim allowing the tube to escape. One solution was to add more rim tape to make the tyre a better fit.
Chris

dennisn

For what it's worth, "Tufo" tubular clinchers work great , are relatively easy to take
off and put on, and stay on the rim if they go flat. Works for me. A little on the heavy
side but nothing is perfect.

dennis noward

aracer

ISTM those have all the disadvantages of tubs along with all the disadvantages of clinchers.