BIKEPGH MESSAGE BOARD ARCHIVE

What specifically do you mean by check out?

I've always run my finger along the inside of the tire while making sure to look so that I don't cut my fingers on glass. That will usually find just about anything, given how sensitive your finger tips are.

Also, always line up the valve stem with the hot stamp on the tire (the brand label) with the label pointing to the drive side of the bike. That way, if you can't find the offending object you can inflate the tube, find the hole and match it up to where that hole would be on the tire.

I've almost never not found the source of a flat and am very hesitant to put a new tube in till I find what caused the flat.

How far apart were the holes? The weren't by any chance just as far apart as the spoke holes?

i ran my finger along the inside of the tire and the rim of the wheel.

it may have been the spokes, but the liner on the wheel wasn't broken or anything....

I've had those mystery flats from time to time. The most recent was just yesterday. When I got up in the morning, the bike having been unused over the weekend, the rear tire was flat. I filled it up with air and it has been fine since then. No sign of any air loss all during the day yesterday when it was locked to a rack outside, no loss of air overnight.

I've had mystery flats too. I think they were due to cheap tires or something getting stuck in my tire just enough so I couldn't feel it over a finger pass, but enough to prick the inner-tube under pressure.

valves are sometimes the culprit and can be undetectable unless you put the tube in some water.

RF: How far inside the rim was it?

also, do you use tire levers to get your tire/tube back on?

You should use a tire gauge when you pump the tires up. You're almost certainly not getting to the recommended pressure if your not using a gauge, and that can lead to pinch flats.

@ Pierce- I typically flatten out the tire a bit when I run my fingers along the inside and that will usually show if anything is in the tire but slightly hidden.

On a related, but side note- I had a flat last night that as I was feeling the tire I found about 4 or 5 small pieces of wire. I have had these before as well as the occasional nail, staple, glass, etc... So with all of this wonderful "stuff" hanging around I was inspired by a local auto tire repair shop that saves all of the stuff they pull from tires on their counter. I think I am going to use a pill bottle at first and hopefully it doesn't fill up too much, but I think it would be interesting to see what I can accumulate over the years.

What is weird is that I will have these mystery flats, I will pump up the tire and not have any more problems for many months. If it were any sort of puncture or pinch flat, I could not imagine it holding air for very long. Sure, a small hole might be small enough to let me get home but if it was large enough to let out all the air overnight, it shouldn't magically close up and hold for months.

is your house haunted?

Twice, I've had mystery flats that turned out to be "I forgot to screw down the Presta valve after topping off the air".

I suppose a strategically-placed bit of dirt might have a similar slow-leaking effect in a Schraeder valve; then, re-inflating it could push the grit aside, so no more slow leak.

No such thing as ghosts.

I had a sequence of mystery flats that revealed itself when the valve stem pulled completely out of the tire.

I think that there was a crack in the tube at the valve stem, which, when bent in some direction would open up and leak all the air out, but when bent in the usual way, would hold pressure nicely. Eventually I realized it when the valve stem pulled away, until then I was confused.

I had a bunch when I was running around 140psi that were caused by having a soft rubber, instead of harder plastic, guards for the spoke nipples.

It was just enough of an edge from the spokes that it would pop them at high pressures

Every flat I change, I do at home. This lets me immerse the tube in a pan of water in an attempt to determine where and how many leaks there are. If a pinch flat put a fairly quick hole in it, that's fairly easy to spot and repair. But often enough, there is a smaller pinch puncture that a visual or tactical inspection would have missed. Air bubbles do not lie. I hate putting a tire back on, only to pull it back off two or three days later because I neglected that step.

I do use tire levers. I think the spokes may be the culprit, since I was flat this morning, and again after work. It's holding air the entire time I'm riding though. Used my last patch this past weekend

Since the basement of mancini's in the strip is basically a bike graveyard with a couple pieces of bakery equipment in between, I grabbed a new tube/tire (none of the wheels fit my bike). The tube and tire are a bit big, so I had to adjust my brakes, and I have to ride that way until I can get a new wheel. I know nothing about spokes, but my boss examined the wheel and liner and agreed that it may be the spokes.

does the inside of the rim look like this?



and:

do you have a rim strip or tape covering the spokes?

yes and yes.

Is your rim strip (a) cloth, or is it (b) plastic?

rubber?

before you do anything drastic, do what Stu suggests and figure out EXACTLY where the leak is coming from.

I found matching pinholes in the tire liner - but not what's causing those. I wiped out the inside of the tire, nothing, wiped off the rim, nothing. my boss found one spoke that she said is a little rough, but that's it.

Just a note on immersing tubes in water, I find I have to wipe a bazillion air bubbles off the tube. If bubbles appear after I've wiped off the surface tension bubbles, then I have a leak.

yeah, I found and patched the initial tube that way, and the second tube, of course, had a leak in the same spot - on the rim side of the tube. there's nothing on the rim that would say, "Hey, I caused that flat," to me.

i've always cursed those rubber rim strips. i've had a few flats because it's impossible to get that thing to stay on straight when putting on a tube and tire. never had a problem with cloth tape, though.

cloth tape, like the kind I use as a bandage wrap?

a little bit thicker, i think. kraynick's sells the same cloth tape for rim wrapping as for handlebar wrapping (presuming you want cloth tape for your handlebars, as opposed to, say, cork).

I tried using cloth medical tape in a pinch once, something about the adhesive completely messed up the tube, I had seething lines of air holes, wierd, if that's what you're thinking, don't. Buy rim tape.