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tyre deformation problem - any suggestions/thoughts

mellisr1mellisr1 Posts: 67
edited December 2009 in The workshop
On my hybrid I've got conti travel contact tyres ( ... tact.shtml) for their punture resitance

Cant fault them really and the bit of glass I ran over on Monday I think would have got through almost any punture resitant tyre. I don't think the rear went down straight off (large shard still sticking in) and i found the broken bottle later and it was only 500 yards from work.

In the dark going home I rode on it for about 10 feet before I realised it was flat as a pancake. I replace the tube, extracked the glass but as I rode home could feel a oscilation as though the rim had buckled.

Upon investigation I noticed that apporx 1 eighth of the tire circumference was seated lower in the rim. I measured it and everywhere else it was 5cm from inner edge of rim to mid point of tread. this part of the tyre was sitting about 3-4mm lower (only noticable really as the reflective trim on tyrewall shows it up).

Nothing I do can get it to seat properly. I've tried inflating slowly, taking right to psi limit, rotating the tyre to another part of wheel, putting it on the front wheel, running it backwards. Still the same area sits too low and it must be this which gives me a lumpy riding feeling.

Anyone ever had something like this? could I have damaged the sidewall/metal bead in the tire just running it dead flat for such a short distance (no visibale damage to the tyre though)?

It's really weird and any thoughts/suggestions how to sort would be great. or should I just bin it rather than risk riding on it? i'm a bit annoyed as it's only about 3 months old!

After I hear thoughts, I might even contact continental - just wanted to check if it was a well known thing for tires to do this!

many thanks
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  • will3will3 Posts: 2,173
    Yes, some tyres on some rims are a complete censored .

    I've used the conti Travel Contact on a Sun-ringle BMF rim. it was a sod to fit.
    Your best bet is to use some lubricant on the bead (washing up liquid) and just work at it.

    Was it like this when you fitted it first time?
  • didn't notice any problems fitting the tyre before the flat but will try the washing up liquid trick.

    otherwise I'll contact Continental as they have a guarentee on this tyre if it punctures in less sthan 12 months. I've probably lost the guarentee but its obviosly very new and coupled with the seating/deformation problem, they might replace it!

    Looking for a friendly & welcoming club in Warrington/North Cheshire area ?
    Try North Cheshire Clarion :
  • The motor trade use tyre fitting soap or tyre fitting paste.
    Ordinary soap (not dry, just wet enough) will do a similar thing.
  • You may have damaged the tyre, but are you sure the tyre is properly seated?

    If you have inflated by hand, there won't be that much pressure. With wider rims, you sometimes need quite a lot of tyre pressure to get the tube to force the bead fully into its seat. For example, I run 25c's on 29er mtb rims. These are probably too narrow for the rim and I need at least 80 psi before I hear the satisfying "ping" of the bead riding up from the track with the spoke holes through it, and against the back of the braking surface.

    If you are concerned about damage, get the tyre off and inspect the inside. I assume you can't see anything on the outer tyre wall to indicate that the flat running did any damage,so If the surface on the inside is at all broken up, the tyre is a gonner.

    I would be suprised if the rim is damaged, unless it was already old. I've run Mavic road rims flat for a couple of miles before now and they get chips and ;little dents from stones, but don't deform as a whole unless you really crunch a pothole or something like that. They have to be quite strong to hold the tyre on, right?

    If you are worried, take the tyre off and rotate the wheel in the frame. If there is still a huge wobble, perhaps you have a problem. Try to see if you've deformed the side walls at all - if they have been pushed out by the incident, they might have been too worn and thin anyway.

    My guess is that this isn't your problem though.
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