Slow leak from Schwalbe presta valve tubes

[julk]

Does anyone else have this?

My recent new Schwalbe tubes have had a slow leak which puzzled me.
Extensive searching revealed that the tubes had no holes in them.
Eventually I found the valve core was not quite tight enough.

I invested in a Park Tool valve core tool and tightened my valve cores, a little tightening was enough to stop the slow leaks.
Julian.

[IanW]

Sadly yes I have experienced the same problem with Schwalbe presta valved tubes.
I installed 4 tubes onto 2 RSTs
Unfortunately while 3 of the installed tubes hold their pressure just fine for several weeks
one of them drop-s from 5-bar to under 3-bar within the week.
More unfortunately still no abound of presta valve core tightening, nor removal, cleaning and re-inserting fixes the problem.

[JimK]

I had a flat a couple days ago, a staple right through my Marathon Plus Tour. Patched the tube & remounted the tire & pumped it up with my Lezyne Micro Floor pump. Unscrewing the pump head... ach, the valve core came with it and all that air came racing out. I think I bought a valve core wrench but I have no idea where it is. I snugged the valve core down with pliers. Second filling held!

[Andre Jute]

Duh. Me too. Just as well I put off demounting the tyre and looking for holes. I had the problem intermittently on two new tubes (I fitted new tyres and tubes after two horrendously dangerous flats last year) but it seems to have fixed itself on one tube with no action from me except to pump it up; possibly just closing the valve tightened the core. The other one is flat every few days... I'm ordering a core tool tonight. Thanks, Julian.

[martinf]

Until fairly recently I used Michelin latex tubes with non-removable cores, still got them on my old 700C bike. In recent years, the quality of these sems to have declined, or maybe the stock in my LBS is just too old (latex ends up by perishing), so I now have Schwalbe butyl tubes on most of the family bikes.

I spent a fair bit of time looking for my first leak with Schwalbe tubes, the pressure wasn't sufficient to reveal it when immersing the tube in water. I replaced the tube.

The second time I had a leak I tried unscrewing the valve and found out that the core is removable. I don't have a special tool, so just tightened it with a 6" adjustable end wrench.

[Andre Jute]

Slow leaks fixed by tightening the valve cores. Thanks, Julian!

[julk]

Andre,
Glad it worked for you.
Julian.