Giant Doofus

Update: It wasn't the rim tape after all. Still exploring possibilities.

My spouse hadn't been on his bike for years when he decided to resume riding this summer. I was delighted and went out to get him some new tires, tubes, and some Velox rim tape. I took his rear wheel into the LBS to be sure I was getting the right size for everything. Things looked good throughout our first ride, but the following morning, his rear tire was flat. It looked like the problem was a faulty valve stem, so I replaced the tube and we headed out the next day. Again, the following morning, flat tire. The tires were always fine for our rides, but flat the next morning.

We took the tubes into the LBS and the clerk assured us the problem was a batch of faulty tubes. (They did replace the tubes for free, which was nice.) Next day, we got a repeat on the front tire. Five consecutive rides and five consecutive flat tires later, I took the wheels back in. This time we were greeted by the manager who looked at the back wheel and told us the rim tape was too wide and was probably rubbing against the tube. We swapped out the tape and, voila, no more flats.

Well, at least I've had a lot of practice changing flats now!

Circulate

I liked this story, and then LOL'd when I saw how well your username relates

TransitBiker

The shop that "fixed" my first broken spoke had the rim tape off-center, and the worn-in spots where the tube presses into the hole in the rim were mismatched. After this caused a flat, i re-positioned it and it's been fine ever since!

- Andy

J.C. Koto

I'm curious, what was the rim tape size that was causing the problems and what size did you need to fix it?

Giant Doofus

I need to update this post. It turns out the rim tape wasn't the culprit after all. We did get two rides out of the tires after swapping out the tape, but flatted after the third. Grrr... At this point I'm a little frustrated with the LBS since they originally assured me that the first round of rim tape was the right size, then told me the problem was the tubes, and finally said the problem was the tape they had recommended for my rims.

I think the original was 17mm Velox, and we switched to 10mm rubber.

J.C. Koto

That's a bummer.

Ok, sorry if this is too basic a question, but have you *thoroughly* examined the inside of the tire for anything that might be causing the flats? Sometimes it's something really ridiculously small. It's often suggested to use a cotton ball to lightly rub the interior surface of the tire since the cotton will easily snag on little pointy/pokey things that are easy to miss otherwise.

I've also seen a post here on bikeforums where someone kept getting mysterious flats until they realized there was a small nail embedded in the ground right where they'd park their bike so, unlikely as it sounds, it's something to consider.

TransitBiker

+1

I had a sharp stone break off in the tire after one flat, and the piece caused another a few days later. The cotton trick works very well, but a good visual inspection at the puncture site, be it road side or rim side, should clue you in on what's going on in combination.

- Andy

BobbyG

I have started feeling the inside of my tires after a few too many flats last summer. Goat-head thorns will embed in the tire and the head will break off leaving almost impossibly thin stems slightlybpoking through the tire like a solitary beard-stubble. Weird. Last summer I put liners in both my road and 26x1.75 commuter bikes. Have had one flat since where a goat-head thorn attatched itself by the rim! Love the tire liners!

Fishmonger

I put liners on my commuter, and it's been great ever since. They aren't a guarantee against flats, but since my frame pump broke and I'm waiting for another, I feel more comfortable riding anyway.

Booger1

When installing tires,line up something with/opposite the valve stem,so you can use that as a reference to find WHAT is in your tire.Alot easier than searching the complete tire for stuff.

When at home,use a cotton ball to find stuff in your tire you can't see....Put a cotton ball in your tool kit.....For you weight weenies,use a cig butt...

PaulRivers

Yeah, what you should do is, when you take off the tube fill it up with air again and figure out where the flat is happening. Trace it back to where it's happening on the tire - is it on the inside? Is it on the outside? Look around for anything that might be causing it to flat. But mark it and keep track of it. Next time you have a flat - is it happening in the same place?

One trick people will use it lining up the logo on the tire sidewall with where the stem goes through the rim so it's easier to track the spot back when you take the tire off.

Andy_K 

I was suspicious of this. Velox rim tape is fairly soft, and I was having a hard time imagining a flat caused by using a strip that was too wide. I mean, I suppose you could wear a hole in a tube by rubbing it against cloth, but it would take an awful lot of rubbing.

+1 on the suggestions to find the hole in a tube and look for something in the wheel or tire there.

dynaryder

Definitely find where on the tube the puncture is. If it's on the wheel side,carefully run your fingers around the rim to see if you can find a sharp spot(you could do the cotton ball trick,but I like to feel for it). If it's on the tire side,turn the tire inside-out. Sometimes,a tiny bit of something can get into the rubber,but it only sticks out when the tire deforms under pressure when riding it. Turning the tire inside-out will usually cause the object to pop out where you can see it.

spivonious

Have you checked the tube for punctures after each flat? Pump it up so it holds it's shape, and submerge it under water. You'll find the bubbles coming out wherever the leak is. This would rule out the bad valve stem theory. If the leak is on the spoke side, you have bad rim tape. If the leak is on the side, could be pinch flat. If the leak is on the tire side, probably something stuck in the tire.

Darth Lefty 

I'm going Stan's tubeless on my next thing, because why not try something new for fun?

PatrickGSR94

Hate to hear that, rubber is junk for rim strips. I got some cloth strips from the LBS awhile back to replace the rubber ones currently in my KHS's bike rims, just haven't gotten around to doing it yet.

TransitBiker

My cruiser had rubber, my breezer has polyurethane. I'd use cloth, but i ride in the wet too often.

- Andy

Giant Doofus

@J C Koto - yeah, we checked the interior of the tire very carefully. Nothing there. All of the holes have been on the rim side of the tube and most have been near the valve stem. We've also been careful to make sure the stem is straight and that we don't strain it putting the tire on.

We're flummoxed. I'm starting to wonder if the problem might be the new tires. We got him 38 mm tires with a Kevlar belt. His old tires were 32mm. The bike shop guy was confident these would fit and we haven't had trouble getting them on the rims (well, except that the fit is tight as you would expect with a tire like this).

I'm grateful for any other thought BFers might care to share. We'll be back in town in a few days, and I plan to take his bike into the co-op to see if anyone there can figure it out.

TransitBiker

K, this may sound stupid, but i just thought of something........ Have you checked the tube packaging to see they are size matched to your tire? I had an old 26 inch spare tube that i bought when i had my cruiser, but it would not work for the size tires i have on the uptown. They were designed for fatter tires. I had to go buy a new tube when i had a flat plus tire blowing out (coming apart on bead). So my thinking is, you may have a tube designed for a tire skinnier or fatter than your tire.

- Andy

Giant Doofus

Good thought, but I've already checked that. The tubes are appropriate for the 38mm tires.

alan s 

Related to this, I had slight sidewall damage to a tire, so to minimize the chance of it getting worse, inserted a bit of Tyvek for a boot. Worked great, but then recently bought a pack of Park Tools boots, and replaced the Tyvek. Well, on my ride home tonight, I got a flat caused by the edge of the Park boot. Can't believe I paid for boots that caused a flat, when the free Tyvek worked perfectly. Don't bother with these except for emergencies, as labeled. Park Tool Co. » Park Tool Co.

Andy_K 

Very strange. Any chance you're using presta valve with a schrader hole and no adapter?

J.C. Koto

Man, that's gotta sting a little.. Makes for an amusing anecdote though!

Giant Doofus

Nope. They are Schraeder valves, which is what the rim is drilled for.

I've noticed that the rims are slightly out of true. Seems like an unlikely culprit, but I'm running out of ideas.

TransitBiker

Ok, i got an idea. Try using plain talc when inserting tube, a moderate amount, coating most of the inside of the tire evenly as possible. I did this after a few tubes burst in the mounted tire as i was inflating. First time i nearly went deaf from the bang. Second time i heard the stretching sound & covered my ears Used talk ever since & never happened again. Before you put new tube in, try water testing it for leaks, dry off, insert with the talc method. Also, check for patches etc, as some skeevy people will return patched tubes.

- Andy