Damaged valves

[Willy Nilly]

Hi,

I'm have a 2013 Mongoose Tyax Expert 26er with some Alexrims Ace24. Bought my it secondhand and have been riding it a bit recently.

For 2 weekends in a row, I've ended up walking back to my car due to punctures in my back wheel. This despite having tyre liners and sludge-filled tyres.

2 weekends back, still using my original tubes with schrader valves, I got what I thought was a puncture and had to walk about 1km to my car. When I examined the wheel and tyre, I noticed a tear in the schrader valve right where the rim and valve meet. 

I decide to get sludge-filled tubes and acquired some from CWC. Got the Kenda ones with the presto valves.

Last weekend, with the new tubes installed, I ended up walking 6-7km back to my car. Got a puncture, sludge did its thing and I pumped up my wheel and set off again. About a km away, got another flat and this is when I heard the air escaping at the valve. Checked and sludge was seeping out at the valve.

Do I just have worst luck or am I doing something I shouldn't?

[David Marshall]

Looks like your rims are made for Schreader valves.  Presta valves, as in the 2nd pic, are smaller in diameter so they will chafe in the larger hole in the rim.

 

The damage on the Schreader valve could be from a sharp edge on the rim or from pumping the tire with a inflexible hand pump.

[dirtypot]

Why not just convert to tubeless?

[Eugene]

You are using the wrong tubes, exactly as David said.

 

The tube in the top picture uses a car like valve, which is what your wheels are designed for. The damage to that valve suggests that the tube was not correctly lined up with the rim and the valve was probably sitting skew where it protruded from the rim.

 

Make sure you get the correct tubes, when you insert them make sure the valve is lined up perfectly and to prevent the friction David spoke of, sprinkle a little talcum powder around the valve area.

 

Also when pumping, make sure the pump sits square on the valve and you don't put any undue sideways pressure

[NicNacDH]

Why not just convert to tubeless?

This is all you need!!!

But still with a schrader valve.

 

The picture shows my front tire, with 7 thorns on that ~ 200mm .... this makes theoretically about ~70 all around. I never walked back to my car, because of a puncture.

[xcd]

Mtb with tubeless is the only answer - or - you are going to get so frustrated fixing punctures.

[Willy Nilly]

Thanks, everyone, for the feedback. I am going t definitely go tubeless. I was not aware that the rim needed to match the valve. Thought getting the presta valve was the way to go, but this is not the case with these rims.

 

Again, thanks everyone.

 

What do you guys think if a ghetto conversion? Been reading a lot about it, even watching some videos. Some swear by it, while others have issues upon issues...

[scotty]

Done correctly ghetto works, I have a set of 26" Alex rims set like this. 

[JXV]

Hi,

 

I'm have a 2013 Mongoose Tyax Expert 26er with some Alexrims Ace24. Bought my it secondhand and have been riding it a bit recently.

 

For 2 weekends in a row, I've ended up walking back to my car due to punctures in my back wheel. This despite having tyre liners and sludge-filled tyres.

 

2 weekends back, still using my original tubes with schrader valves, I got what I thought was a puncture and had to walk about 1km to my car. When I examined the wheel and tyre, I noticed a tear in the schrader valve right where the rim and valve meet. schrader_torn.jpg

 

I decide to get sludge-filled tubes and acquired some from CWC. Got the Kenda ones with the presto valves.

 

Last weekend, with the new tubes installed, I ended up walking 6-7km back to my car. Got a puncture, sludge did its thing and I pumped up my wheel and set off again. About a km away, got another flat and this is when I heard the air escaping at the valve. Checked and sludge was seeping out at the valve.

presta_torn1.jpgpresta_torn2.jpg

 

Do I just have worst luck or am I doing something I shouldn't?

Schrader valves need a 9mm hole in the rim. They simply won't fit in a rim drilled for presta (8mm). Likewise, Presta valves may not be reliable in a rim drilled for schrader. So go back to Schrader tubes.

 

It seems your rim might have a sharp edge at the valve hole or your pump is causing the damage by pulling on the valve stem during pumping.

 

You can also get this type of cut near the valve if the tyre rotates on the rim under hard braking or acceleration. This can happen if the tyre bead is a loose fit on the rim and usually made worse if you run low tyre pressures for more grip.

 

You can get slime filled schrader tubes and I suggest you also get a pump with a flexible hose connection to the valve ( Lezyne makes a nice one).

 

Before fitting any more tubes, strip that rim and trim or file off any sharp edges at the valve hole. Also check the rim liner strip that shields the tube from the spoke holes. Then make sure the tyre bead does not rotate on the rim when seated. If it does, run higher pressures. You can also build up the rim diameter with some rim tape if you have to.