This broken valve thing keeps happening and I’m not sure why.
My guess is that it could be the orifice on the rim, someone told me it could be caused by the pressure on the tire so if you have a good idea of what could I do differently or a fix I may apply it would be perfect 👌🏽
by elmaiik
17 Comments
One of the best ways to prevent this is to keep enough air pressure in the tube so that the tire doesn’t rotate around the rim and drag the tube with it.
You can also put some talcum powder inside the tire which can help prevent the tire from sticking to the tube.
You can see the metal at the hole, that is probably causing such punctures. It could be solved by replacing the rim tape.
It’s probably getting pinched by the hole in the rim. You can sand that smoother with a thin file. Riding at pressure that’s too low or skidding a lot can also slide the tire/tube within the rim, forcing the stem to a weird angle and leading to that kind of puncture.
deburr the hole and add a piece of tape. And make sure the stem is reasonably centered and not pushed up against one side when installing the tube.
I strongly recommend Schrader valves. They’re thicker in diameter, which reduces the number of occurrences such as the ones you described, and they have a more sturdy, more easily available and more easily replaceable mechanism.
do you tighten the nut on the outside?
Replace the rim strip with tubeless tape. It stays in place and is actually thinner. Also, don’t tighten down the retaining nut so much on the valve.
You might overtightening the nut. It should be barely finger tight.
Back when I first (well a few months after my replacing my first flat) started using Presta I blew through a bunch tubes in a week before I asked a mech at a shop. I actually stopped using the nuts altogether for a bit lol.
OP, what PSI are you inflating to ?
The rim is drilled for presta and not the larger Schrader valve, correct?
With new tube. Coat the tube in baby powder then install under tire.
I used todo this for many years it stops the inner tube gripping the tire. Pretty sure I learned this from Sheldon website and it just works.
Baby Powder try it.
And clean up the edges of the hole with a file, fine sandpaper
File the hole to be smooth. Put a rim tape with good protection around the hole.
Throw away the nut. Dont use it ever again. You might overtighten it.
I’d line the rim strip with the hole slightly better, make sure the edges of the hole are debuted/smooth. Also make sure the the nut on the outside is snug and the pressures in your tire are sufficiently optimized
This happens on dirtbikes when you run your air pressure too low without a rim lock. The tire spins, but the tube cannot, and it rips at the valve stem.
Are you running super low pressure and maybe doing skid stops? Is this an ebike?
I’ve started placing the nut on the inside, but also you can easily use some tape or stickers. No failures, over 4k miles completed since I started that.
Stickers:
[https://www.amazon.com/SEADEAR-presta-Stickers-Mountain-sticker/dp/B0BB98Z7Q8](https://www.amazon.com/SEADEAR-presta-Stickers-Mountain-sticker/dp/B0BB98Z7Q8)
You may be over tightening the valve cover. I’ve experienced it 2x with my e-bike before
Hot take, could be the tyres, sounds weird, but bare with me.
Kenda had a whole bunch of tyres that were ever so slightly out causing the tyre and tube to slip ever so slightly on the rim.
The rotation caused the valves to break at the valve just like that, because the tyre and tube were rotating on the rim.
so it’s another potential reason this could happen.