Need help with flat tires

[icecream]

Hello all i need some help here i'm trying to widdle down the factors and see what is causing me to keep getting flats. I don't know what the hell is going on but i keep getting one flat tire.

here are the things i've checked i bought brand new rim strips, keep the tires properly inflated, both new tires & tubes, using a presta valve for a rim that has a hole for prestas.

700x25 tires, i'm using 700x18 tubes I know it's kind of a tight fit but if I pinch the tube at the stem upward while mounting the tire it fits on the rim perfect. any other ideas ? i've already got a bad taste in my mouth about slime the stuff is a damn mess & not worth the hassle.


Thanks so much !

[DaveM]

You need to look at the holes in the tube. Are they small punctures or larger tears, splits? Are they on the inside side (toward the rim) or on the outside (ground side)? Do they keep happening in roughly the same place (in terms of distance from the valve? These should help point you to the cause.

It may something as simple as something sharp embedded in the tire that keeps puncturing the new tube, or a metal burr on the rim or valve hole.

[xerxes]

What make/model tyres are you using?

Also, how often are you getting flats, are you getting another shortly after repairing one? If so, check the inside of the tyre before you repair or replace the inner tube. I usually feel around the inside of the tyre to make sure that whatever it was that caused the original puncture isn't still lodged in the tyre waiting to punture the new or repaired tube.

[cyclerUK]

I always make sure that when I remove a punctured tube that I note which way I take it out.
Then I locate the puncture, either by inflating the tube or sometimes it's obvious. You can usually feel air coming out of a small puncture if you put the tube next to your cheek.
Then I examine the tyre at the spot relative to where the tube is punctured.
Usually, in our area, it's a thorn and these can be hard to find as they brake of easily in the tyre. Sometimes you need to turn the tyre inside out, at the spot, to find the cause.

[Jordan300]

I experienced a similar problem like this after I went through 4 tubes and a new tire.. I found out that It was a burr on the rim that was causing all the punctures.

[009jim]

Do you ride through glass? Sometimes on my commute you see places where wallies have smashed a bottle on the bike path. Of course I don't carry a broom, nor does anyone I know, so that glass stays on the track for ages. Sometimes I actually get off my bike and carry it over.

[DrHenley]

My daughter was having the same problem on her bike. We went through 5 tubes in a week! I was pulling my hair out trying to figure out what to do to keep from changing tubes every day.

I went to a reputable bike shop and asked for advice. They recommended going to a slightly larger tube. She has 700Cx23 tires, and they told me to try 700cx25 tubes.

Well, long story short, the larger tubes worked like a champ! The tubes hardly get stretched, so the tires themselves are taking all the pressure. The tubes are simply sealing the tire instead of trying to contain the pressure. Since the tube walls aren't stressed, they can take a lot more abuse. She was finally able to go for weeks without a flat.

Within the last few days, she ran over a glass shard, and it punctured the tube, but the tube held together and sealed the hole well enough for her to ride a couple of days before the air leaked out. With the smaller diameter tube, she would have either had a blowout, or been flat within minutes.

Ditch those 700cx18 tubes and get some larger tubes!