Why does my wheel keep going flat?
 

I just bought a new wheel and had this bike store out here assemble it. They gave it back to me- no rim tape. But no big deal. I had rim tape from Performance (cloth rim tape, performance brand). I put that rim tape on, then put the inner tube/wheel on and blew it up to 100 psi. Within an hour, it was flat. I figured it was because I used an older, previously used inner tube, so I went back and pulled an inner tube from the box and put that one back on the tire. I put more air in the tire. Now this morning, the tire is flat again. :-/

Does anyone have a solution? I'm now wondering if it's the rim tape. Maybe I should put the second roll of rim tape around the rims also, because I'm wondering if the spokes are poking through the inner tube.

Wheels= Campy Ventos, btw.

Thanks,

koffee

The first question is always: Where is the hole? On the outer side or the inner side of the tube? How big is the hole?

If on the inner side, see how the hole in the tube matches up with the wheel ( in either direction). Is there a gap in the tape there?

Are these new tires? If not, maybe there's a tiny piece of glass stuck in the tire.

You know, I have no idea about the hole yet. I'm out of practice- didn't even think to check for the hole on the first tube- just threw it away, but the second tube is still on the wheel. I'll check it when I get home from work later today.

I thought I rolled that tape on there pretty tight and smoothed it out pretty good, but maybe I put it on incorrectly. Is there a method to the madness when putting on rim tape? It extended the full length of the wheel and overlapped by a few millimeters when I reached the end of the wheel.

I'll have to check on these things when I return from work. Thanks.

koffee

P.S. Brand new wheel, tire, and tube

Speculatin on all the possible causes is a waste of time. Find the original tube and look at it, or wait for this one to flat. Rim tape is a no brainer. If it's wide enough and it handles high pressure you shouldn't be having a problem with it.

Well, it's the plan, but since I live in a high rise, unless I dumpster dive, that first tube is straight up gone. I'll have to wait until I get home and pull the new one to find out what the heck is going on. The more I think about it, the more I'm thinking it's the rim tape, though. If the tube confirms my suspicions, I've got some better rim tape at home. I shoulda went with Mr. Tuffy to begin with!

koffee

Mr tuffy does not help with rim tape related flats (obviously). Even some "high pressure" rim tape need to be doubled up to prevent flats. I've seen open pros with particularly bad reinforcements with lips that caused flats.

Hmmmmmm.... good to know. I'll have to find out what the max pressure is for my wheels while I'm at it. Thanks for the tips!

koffee

New wheel and new rim tape. Almost certainly you have a tiny bit of spoke hole exposed. It doesn't take much. Take off your tire and tube and carefully examine your rim tape. If you can see the tiniest little arc of rim hole, that's it. When you pump up your tire you have 100 psi air pressure forcing the fragile inner tube against the sharp metal edge of that hole.

Realign your rim tape to cover it up and you'll be good-to-go.

To add to the previous response you need to also look at what the hole looks like.

If on or near the road side of the tire a pinhole will be a nail, staple, etc. A small slit will be glass. In each case check the tire at that point, both on the inside and outside. It's best on the inside to feel with your fingers, but be careful!

If on the rim side it will generally be either side-by-side slit punctures ("snakebite"), a large roundish puncture or a single curved slit to one side, often with a bubble next to it. the first is a pinch flat - underinflation or too narrow a tire for the rim, resulting in too little rim to pavement distance. The second is a rim tape/spoke hole problem and the third is a spoke poking through. I'm sure it's not an issue in your case but flats can also happen from stress at the valve stem from underinflation and the tube migrating (stretched on one side of stem, folded on the other).

You did not mention a blowout so I assume that is not an issue, but a blowout will be quite a big tear and is ALWAYS either improper mounting, tire bead defect, or serious damage to the tire's casing - never the fault of the tube.

Please don't call tyres wheels. It's beyond noobish.

Dood, deal.

I'd suggest you not act like a backwards, snobbish countryfied hole that needs to keep your dumb *sssed effin comments to yourself. If you can't spend your time commenting on the relevant question I'm asking so you can make yourself feel good, keep it shut. Had you read the sentence correctly before making your stupid comment, I did put the inner tube/wheel back on the effin bike. Then I added air. I don't put air in the tire before mounting it on the bike. But since you obviously need a complete blow-by-blow, and you don't seem to have the intelligence to read into something before making your ridiculous statement, then here:
"I put that rim tape on, then put the inner tube onto the tire, then mounted the wheel on the bike and added air". I'm sorry I don't speak stupid, but I'll try to use little words and write out the entire blow by blow analysis so you don't get all insulted by noobie talk again. :rolleyes:

Sorry to everyone else- I get tired of snobs who like to comment when they clearly have nothing of value to say.

For everyone else with helpful comments, many thanks.

koffee

Well I guess that leaves me out.

This guy found the hole or not?

One trick when mounting tires and tubes is to establish a reference between the two. You can do this any number of ways, such as putting the tire label at the valve, or making a small mark on the tire wall also at the valve. This will save time and help you locate sources of punctures because once you find the leak in the tube, you'll know where on the tire to look for the cause.

A common shop practice is to place the portion of the tire that indicates proper pressure next to the valve stem, on the drive side of the bike. That accomplishes the above goal and makes proper inflation easier as well. If not already mounted that way all you have to do when diagnosing a flat is to leave the tire on the rim and then place the tube back next to the tire/wheel as you reinflate, so that once you find the hole you can find the matching place on the tire/rim.

Actually, I agree with Kimmo -- using the right words is very important if you want people to be able to understand your question. So he said your description was Noobish, well, it was! Admit it and move on!

Using accurate descriptions, terminology and spelling is both more efficient as well as respectful of those with whom you are trying to communicate. That being said, if you don't feel someone is being clear in that manner dismissive attitudes and words are not going to improve the situation.

think of your bike as your body, during intimate moments with your girlfriend you wouldn't want to confuse her with confusing information.

Without knowing where the hole is in the TUBE you're not any closer to finding the CAUSE of the flat in your TIRE that is on your WHEEL.

That was helpful advice, idiot.

http://i4.photobucket.com/albums/y11...cryaboutit.jpg

The OP installed the rim strip like she does the Mr Tuffy tire liners?

Don't assume. Koffee as I remember, is a female and a former mod. though I can see how her intemperate reply might tend to confuse a little.

Check the valve- if it's a presta valve and the nut is not tightened down, air can leak out.

If it's a schraeder valve, the pressure spring (or whatever it;s called) may be loose, even on a brand new tube. I always check them on every bike I build or repair. It's a little tiny detail but you'd be surprised at how often they are loose.

Or it could be any of the issues everyone else has mentioned:
- valve being cut by sharp edge at valve hole in rim
- rim tape not completely covering spoke holes or eyelets
- a bit of glass or wire or something in tire tread
- a spoke protuding beyond the nipple and/or beyond the spoke hole
- a plainly defective tube. It happens. They are cheap and made by the millions on a weekly basis.
- a pinched tube when installing with tire (tyre??)levers.

If the bike wasn't ridden at all and it's a new tire and tube, Mr Tuffy's would not be a concern. It would not have prevented a flat.

I've had bad luck with one layer of tape, especially when stretched too thin. The tube will flat on a spoke hole through that if you venture up to 100psi or higher.