Finding leaks in latex

[tmarcus1076]

Anyone have any tricks finding slow leaks in latex tubes? Not the usual leakage, going flat overnight. I hate throwing tubes out and patch them, but if I fill the tube too much it gets a bubble in it and I can't put in enough pressure to find the leak. Tony

[upstate burner]

I've also blown a tube up until the shape distorts. I've been able to adjust the amount of air I put in, to not allow it to get to that point.

Before that though, I look for a small black dot on the tube (mine tubes are pink) at the puncture point if possible. A majority of the time I get a small dot, which looks like a ballpoint pen dotting an "I". If a dot is not found then I partially inflate the tube then submerge the tube in a sink to look for bubbles. If a sink isn't handy, soapy water will visibly bubble up from an air leak.

[Tandem Rider]

Are you submerging it in a sink of water while it's inflated?

[upstate burner]

Originally Posted by Tandem Rider

Are you submerging it in a sink of water while it's inflated?

Yes. Start at the valve and push sections of the tube below water surface. Keep going around the tube until you see bubbles coming out of the tube.

[kramnnim]

Sometimes I have to inflate the tube to where it bulges in one spot, and then force the bulge all the way around the tube. Submerge the section that is bulged. Takes a long time.

[steamer]

I thought going flat or nearly flat overnight was to be expected with latex tubes? I know its true for my tubulars that have latex tubes.

If you have break out a pump each day no matter what, is it even worth it to try to repair the slow leak?

[Mark McM]

Originally Posted by steamer

I thought going flat or nearly flat overnight was to be expected with latex tubes? I know its true for my tubulars that have latex tubes.

If you have break out a pump each day no matter what, is it even worth it to try to repair the slow leak?

Losing 20-25 psi overnight is usual with latex tubes, but going totally flat is not. At the normal leakage rate, you might lose 5-10 psi over the course of a ride, which is usually tolerable. But at higher leakage rates you could end up with a too soft tire by the end of a ride. So yeah, if it is going flat overnight, you'll want to fix it.

I'll second the recommendation to do the water submergence test. The tale-tell bubbles can locate holes too small for the eye to see.

Personally, I only use latex tubes in my racing wheels (which you should top off with air every day anyway). For my other wheels, I use lightweight butyl tubes (some of which are even lighter than latex, but leak down more slowly).

[b021c]

I'll echo the above tests and offer to check your valve and stem extender to confirm they are tight.

[spinarelli]

all my latex tubes,(vittoria pink) developed leaks at the valve, where the valve connects to the rubber. This happens during the second year. Like clockwork. I've never got a puncture during the first year. I've given up on latex and now use regular lite innertubes and just got my first tubeless road wheelset.

[FlashUNC]

Best way I find leaks in them is by throwing them in the garbage and putting in butyl tubes.

[Black Dog]

Originally Posted by spinarelli

all my latex tubes,(vittoria pink) developed leaks at the valve, where the valve connects to the rubber. This happens during the second year. Like clockwork. I've never got a puncture during the first year. I've given up on latex and now use regular lite innertubes and just got my first tubeless road wheelset.

Buy the Michelin latex tubes. I have a few that have been in service for over a decade. Never had a failure at the valve, ever.

[kramnnim]

Originally Posted by Black Dog

Buy the Michelin latex tubes. I have a few that have been in service for over a decade. Never had a failure at the valve, ever.

Do they have removable cores?

[speedevil]

Originally Posted by spinarelli

all my latex tubes,(vittoria pink) developed leaks at the valve, where the valve connects to the rubber. This happens during the second year. Like clockwork. I've never got a puncture during the first year.

Curious - what are the rims like? Classic box-section, deep vee, etc.?

Maybe the failures at the valve are related to the shape of the rim bed.

[NateM]

it seems you have arrived at the achilles heal of the latex tube.Over the years I have had to retire quite a few tubes due to this problem.As you know if you inflate them too much you will get a bubble which is no good for the tube.So what you have is a very small hole which only leaks at high pressure which you cant deliver in a water test.End of tube, cut it up into patches for the holes that you can detect.

[bambam]

Wait 9 months and see if you get a 20 inch mx tube?