Bulging tyre after replacing tube

ErikH

A very newbie question but after replacing a tube on my wheel today I noticed that one side of the tube would bulge out and had to repeatedly reinastall it until it went. It was as if the tyre wasnt sitting correctlty over the tube, that teh edge of teh tyre was flush with the rims...hope that you can understand what I mean? :oops:
How can I avoid this, it was a right pain and took me a while to get it right...

wishitwasallflat

A mechanic once showed me how -

fit one side (bead) of the tyre -
inflate the tube just a little -
fit the tube into the tyre and then work round rolling the other side (bead) of the tyre on to the rim (if its tight make sure the bead that's fully on and the parts of the one that isn't fully on are sitting in the centre of the rim as there is a well there that effectively reduces the diameter the tyre has to squueze over to go on) -
once tyre is on check round the rim that the tube is inside the tyre and none of it it trapped below the bead -
inflate to about 40 psi and quick check round that the tyre is sitting central and even all round (sometimes need to push/pull tyre to get it even a little) and inflate to working pressure.

Works every time for me

andyrr

Way I do it is :
Insert the valve into the rim and inflate the tyre a very little : maybe just 3 strokes of a track pump, just enough to give the tube some shape.
Then work around the tube, pushing gently into the rim : sometimes that is needed repeated a few times as the tube can want to 'roll out' of the tyre.
You want to get the tube in so it is in place consistantly without a bigger section at one place - that can happen if you've inflated the tube a little too much and it has then stretched out.
Once that is in then it's a case of getting the tyre on the rimI do this by workinfrom opposite the vale and then with the last 1/5th or so remaining go around the tyre section already fitted and squeeze the 2 beads into the rim centre. Do that a couple of times, firmly, then do the last section tiny bit at a time. Occasionally I've needed help here : water or even soap if mega tight and if so I'd consider grabbing a cloth (tea towl ideal) to save bruising fingers and thumbs too much. Then I push the valve up away from the rim and inflate to full pressure.
Job done !

nferrar

Sounds like you have the inner tube pinched under the bead of the tyre so that the tyre couldn't seat. Well done for catching it early enough to sort (I only inflate to about 20 psi myself then check both beads all the way around just in case) as otherwise it would go bang with a bit more air in it.

ErikH

"Sounds like you have the inner tube pinched under the bead of the tyre so that the tyre couldn't seat. "

Thats exactly what it was. I have it sorted now but took a few goes to get it right. Haven't changed many punctures so not had much practice - a good thing I suppose.
Thanks Guys,
Erik.