kap 7

I had a tube give out and completely go flat on me ... upon taking it out and inspecting it found that the valve was sliced open from rubbing on the rim. The rubber strip (sorry i don't know the tech term) that runs around the wheel is somehow shifted over from the hole the valve goes through the wheel. I tried to move the strip but it doesn't move - I then tried cutting the rubber a bit to make clearance for the valve to go through but i seemed to be getting nowhere and probably doing more damage than good. I was hoping someone here could give advice on this because I"ve never seen this before and I'm baffled what caused it or how to properly fix it.


valve hole is to right side of opening, half blocked by rubber

HillRider

It's called a rim strip and those rubber ones are notorious for moving and allowing the sharp edges of the valve hole or spoke holes to rub on the tube. Replace it with a Velox adhesive cloth rim strip and you problems should be over. An addition protection for the base of the valve is to punch a small hole in the center of a tube patch and push it down over the valve stem. It will give and extra layer to keep the edges of the rim from the tube rubber.

dabac

Is it really a cut, or has the valve stem broken loose from the tube?
IME, the latter is more common, particularly for people who don’t check tire pressure regularly.

kap 7

It's a cut ...a slit at the base of the of the stem. The stem is still intact with the tube.

Unca_Sam

Right, your stem broke loose from the tube. Like dabac said.
It doesn't have to come off. It's because the tube was under inflated and precessed with the tire, tearing the stem from the tube.

Iride01 

I see a lot of people's bikes that have the valve stem at an angle coming out of the rim. They should come out of the rim and point straight toward the center of the hub. This wasn't yours was it? That is a good indicator of riding with too low a pressure in the tires and the tube and maybe even that rubber rim strip "walking" or "creeping" inside the tire.

Your rubber rim strip is probably just stuck from doing what rubber does when clean and new, it tends to stick. With a little encouragement you might pull it free and get it to line up better. Rim tape will be a much better solution though. Although when done improperly it has it's own set of issues that will also let you flat.

Miele Man

I'd replace that rubber rim tape with a better one such as the Velox brand mentioned upthread. Or you can use one of the plastic rim tapes. Be aware that rim tapes come in different sizes and make sure you get the right size one for your rim.

A BIG advantage to using Velox or any light colour rim tape is that after you get the tire and tube mounted but BEFORE you pump it up fully, you can squeeze the sidewalls of the tire towards each other and look to see if the tire is sitting on the tube anywhere. Doing that can save you from a blowout.

Cheers

kap 7

There were a lot of helpful tips given here but for some reason your wording of "a little encouragement" helped! I couldn't move the rubber with my hand but after reading your post decided to find a good screwdriver and pry it up and sure enough it slid around. I was able to get the new tube in so hopefully I'm good to go. As for the valve alignment I made sure it was perfectly straight and not going into outerspace

I will be honest and say I'm very lazy about keeping up on my tire pressure so that was probably the cause :\

On a side note the new tube is sunlight (?) not familiar with the brand