Tyres


beetle's picture

By beetle - Posted on 26 March 2013

NB: Originally posted elsewhere on the Global Riders Network and appears via syndication.

I've put some new maxis tubeless tyres on my 29 inch rims and when they rotate it feels like I'm riding on an egg. I've pumped them to a high pressure and they have popped into place , but are still not even on the rim. Any ideas. Thanks

[Mod. moved to MTB Gear]

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Scottboy's picture

spray soapy water around the bead area & inflate too max pressure then slowly deflate to your riding pressure , or the tyres could be stuffed I have had this problem with tyres out of true before

Martin Danger's picture

Definitely try the soapy water. If that doesn't work....

Happens now and then that the internal casing of the tyre has a fault with it. Internally, the tyre has threads through it so that it forms the usual tyre shape when you inflate it. These threads could be not just quite right and cause the egg shape. Also (only relates to used tyres) the internal threads could have torn through use/ over use/ large lateral loads resulting in that odd shape.

I did that to a tyre in New Zealand recently. Riding back from the park, I noticed a huge buckle in the wheel. I got back to the hostel and sat down to unbuckle the rim, beer in hand knowing the rest of the evening was gone to playing with my spoke key (yay....).

I then spent 45mins convincing myself that the rim wasn't actually buckled. It was dead straight but it was so hard to believe that the rim was straight when my eyes saw a wheel rotating with a 1 inch left to right buckle. Nuts!

mudnat's picture

both ends? is it wobbling like an egg shape or can you tell by looking at the sidewall? i've had a problem before with the sealant going off for some reason and forming a fat wad in one spot. it shook like a bastard on the stand.

whiskers's picture

Stick a tube in them blow em up to maxx psi or till the bead pops give that ago if you haven't already then go for a spin see what there like Smiling

ptpete's picture

i had this same issue with a tyre that had been sitting in my garage for some time...tried everything from leaving in the sun, inflating to ridiculous psi etc and nothing. threw the whole bike's handling out. i ended up cutting my losses and throwing it away.
p.s.
mr danger, for your own quest for increased knowledge, the threads you are commenting on are called carcass plies, and the whole collection of these plies are the tyres 'carcass'. but what would i know about tyres.

pete

TrekWrekka's picture

So if the suggestions listed above don't work then your tyre carcass is cactus Sticking out tongue

Cotic Tony's picture

Hey Pete
The tyre casing/carcass is made of a few different layers of material beneath the tread rubber a bit like a radial car tyre. These are the plies as with plywood.
The TPI rating is the amount of threads per inch of the strengthening/ support material of the tyre & the ply rating the amount of layers that make up the tyre.
A tubeless tyre therefore may have a sealing ply, a couple of strenghtening plies & the tread thus 4ply carcass.

Higher TPI = more flexibility & the majority of tyres now are 60tpi & downhill tyres may use multiple plies & thicker threads.

On top of this you also have multi compound treads......

Conti & Schwalbe have more in depth stuff on there sites but this is my rudimentary understanding.

Anyone feel free to correct anything above that is incorrect.

And with all of of this technology even the big manufacturers can't get one to be light, fast, puncture resistant, comfortable & grip pea gravel!

T

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