Singlespeed & Fixed Gear - unusual flat - who knows why?

Alright folks, I got a flat today and this is the second time via the same scenario. I was at home in my apartment when I heard a hissing. The first time was late at night and I was unsober and thought maybe someone had tossed some dynamite in the window. This time I just sat and said damn! Anyway...the flat was on my front tire and is a small hole where the valve meets the rubber. This was not due to glass, nails, et al. The first time was in the same spot. Any ideas why my tubes are doing this? Running at too many psi's? Wear and tear? It was an old tube with patches on it so I got some good life out of it, but I'm wondering now since this is how my last two flats have happened. Well, better to be at home than on the road in freezing rain. Thanks.

check the valve-hole for any nicks and burrs, and sand it smooth if there are any?

fsnl
sparky

Use a hand pump on that valve recently? I've had that kill them. Or the valve of a regular pump getting stuck or twisted...

i had one like that; it happend as i was pulling the head of the pump off the valve stem, and when i took the tube out i could see that part of the tube around the stem had been forced into the hole in the rim, which caused it to tear.

if you overtighten that little washer/nut thing around the valve you can cause the rim to pinch around the valve-hole

if you overtighten that little washer/nut thing around the valve you can cause the rim to pinch around the valve-hole

Bam!

I no longer use those things for anything other than the initial pump up, I just keep one in my patch kit....

i got 3 of those same flats in a week last month.

I got a new thing of rim tape (i was using 3 layers of duct tape before) and cut down the PSIs by a tiny bit. i still use the little metal valve screw through.

Havent gotten one since then

Damn...this is like going to the doctor when you have a problem. Except, I don't have to wear a gown, it costs a lot less and it is my bike, not my body. Anyway, I bet that is exactly the problem - an overtightened washer thing. I pump my tires every few weeks and bet I screw them down too tight. Thanks for the responses. Now, I need to go ride my new tube around.

Shoot, forgot to ask. So, are the washer things completely unnecessary to use? They prevent the valve from pulling through the hole in the wheel, right, but that isn't really going to happen.

To avoid that problem do as suggested: check for burrs near valve hole; tighen but do not over tighten the valve stem retainer.
Another suggestion: grab an old inner tube and cut about a 1 square inch patch out of it. Cut a small hole dead center of that patch and slip it over the valve stem before putting valve stem through the hole in rim. That little extra padding wil prevent tube from get pinched/cut.

Rudy and Kay/zonatandem

Shoot, forgot to ask. So, are the washer things completely unnecessary to use? They prevent the valve from pulling through the hole in the wheel, right, but that isn't really going to happen.
yes, the washer/nut things are completely unnecessary. as you may have noticed some tubes don't even have them.

the washers are useful if you are inflating a totally flat tire, usually only when you are using a new tube. after that there's enough pressure to hold the tube in place so you dont really need a washer

It's easy to get the tube pinched under the bead by the valve. After mounting the tire & tube, push the valve INTO the tire then pull it back out. Then inflate.

grab an old inner tube and cut about a 1 square inch patch out of it. Cut a small hole dead center of that patch and slip it over the valve stem before putting valve stem through the hole in rim. That little extra padding wil prevent tube from get pinched/cut.


Exactly right. I was having this problem with my IRO wheels (they flatted on the way home from staten island, and I wasn't even riding.) This fixed 'em right up.

Just in case you're not aware of this - and apologies for pointing out the almost obvious if you are - but is your rim drilled for presta or schraeder? Sometimes if a presta valve is used on a schraeder rim the hole will be so much larger than the valve that the tube will protrude into the rim and get cut by the hole edge...there are plastic grommets to take care of this or simply used the slice of old tube that someone else already mentioned.

if you overtighten that little washer/nut thing around the valve you can cause the rim to pinch around the valve-hole

infact, DON'T USE THOSE AWFUL THINGS. Instead, deflate the tire completely and push the valve stem up from the tire side, lock the pump head and pump away.