Ugh I keep getting flats

[icecream]

Today I was fixing up a bike for a friend and I ran into a problem that seems to be reoccurring. I used both brand new tubes/tires.

the max psi is 90 I put in 85, the tire started to bulge near the stem & then eventually popped. How can I prevent the tire from bulging at the stem ? this seams to happen every time I put a new tube on.

they are both size 27x 1/1/4.


thanks guys !

[cyclerUK]

Faulty tire?
Is the other tyre O.K.?
Are the new tyres the same size as the old ones?

[JohnV]

More things to consider and check.

What is the condition of the wheel at the opening for the stem? Is it larger than normal and does it have any burrs around it that would allow it to puncture the tube when inflated? Do you have a rubber liner between the tube and the wheel?

[Bill]

I agree with cycler you may want to also try a different name brand of tube. It could have been a manufacture defect that QA department did not catch. Also you can inspect the wheel on the inside for small sharp burs.

EDIT: Sorry John you must've just posted lol!

[DaveM]

If the tire consistently bulges out right by the valve stem, it is probably that you are getting the tube stuck under the bead of the tire when you install it (not faulty parts). When you put the tire on, push the valve stem back into the rim before you pump it up, that should get it out from under the bead of the tire. Also, before you pump up the tire, push the side of the tire back away from the rim and look all the way around to see if you can see the tube stuck underneath anywhere.

[icecream]

thanks for the tip guys ! i've tried pushing in the stem prior to pumping it up & it worked. now the only problem is it bulges out on other parts of the tire,not terrible but it is noticeable, they have little notches on the tire all the way around to match up with the rim and the spot where it is bulging you can see the notches, everywhere else you can't. I tried pumping the tire up on the bike flipped over so it's free floating and yet I still keep getting a bulge on the tire.

[DaveM]

It's probably the tube getting stuck under the bead in other spots. Don't ride it like that, it will probably slip off the rim and blow the tube.

I like to pump up the tube just enough to take it's shape, put the tube in the tire, and THEN put the tire on the wheel. Installing with the tube completely flat makes it easier to get it caught under the bead. Also look to see if there's any spots where the tire sits too far inside the rim. If it goes too far in at one spot, it can make it easier for it to bulge out at the opposite point. Lastly, this can be cause by a bad dent in the rim. But it's usually just getting the tire/tube on right.

[cyclerUK]

When fitting a tube put a small amount (and only a small amount) of air in the tube before starting.
This helps to stop the tube getting trapped under the bead of the tyre.
If you can't sort the problem can you take the whole wheel back to the place you bought the tyres and ask them for advice.

Do both wheels have the same problem?