Bulging tyres

[Moonchester]

I've just bought two new tyres (Ultra Gatorskin) for riding my mountain bike on the flat. They are thin tyres (26 x 1.125) so I bought a couple of inner tubes to match. But both tyres spin unevenly, with about a third of each one bulging above the rest. The inner tube is definitely the right size (25 x 1.0 to 1.15) so what might I have done wrong?

 

[Steve Austin]

They're not seated properly. let them down, put 10 to 15 psi in them then rock them quite hard on the rim. inflate to max. Check they are round and how you want them and let some air out (if you need to) to required pressure.

 

[Moonchester]

Thanks Six Million Dollar Man. I thought it might have been something to do with the way they sit on the rims. I'll try that.

 

[Jamie Stokes]

What size rims are they on ?

 

[roadiewill]

ive had that problem before, you've just gotta stick at it till they're good

 

[briank]

Dusting with talcum powder before you fit them makes getting it right easier.

 

[goo_mason]

I was taught to inflate them slightly, then work your way around the tyre, bit by bit, squeezing both sides in towards the middle of the rim. That should make sure that the beads are sitting correctly on the rims before you inflate the tyres fully.

One other cause of 'bulging' is usually around the valve. Again, with the tyre only slightly inflated, push the valve half-way back into the tyre and then work the tyre beads down properly onto the rim before pulling the valve back out fully.

Hope that helps !