Has something changed in tyre valves?

For discussions about bikes and equipment.
Roadster
Posts: 443
Joined: 26 Jul 2016, 2:12pm
Location: E.Lancs/W.Yorks border

Re: Has something changed in tyre valves?

Postby Roadster » 23 Mar 2018, 2:37am

I don't think my Schwalbe cores had been fully tightened from new but I'd had no problem with other pumps until I used the Lezyne. I didn't have any threadlock handy so just tightened the cores down firmly with a small open-ended spanner.

The Lezyne has an exceptionally grippy connector (nothing to do with the hose pressure release button, by the way) but the tightened cores withstood rigorous testing and I've used it a couple of times since then with no problems. If you've used threadlock on yours and tightened them down firmly, they should be fine.

FasterFerret
Posts: 201
Joined: 27 Jul 2015, 3:19pm

Re: Has something changed in tyre valves?

Postby FasterFerret » 9 Jun 2018, 10:08am

Had exactly this problem a few weeks ago...

3 hours in to a 5 hour ride the forecast 'light showers' turned torrential. 4 hours in I got a rear puncture :(

No problem I thought, quick change and I'll be on my way. I pulled out a brand new Continental Race 28 tube, refitted and reinflated using a CO2 inflator (interesting just how much ice those things can produce in the rain...). When I removed the (screw on) inflator, woosh - all the air right out of the tube. It took me a few seconds to work it out, thought that I had snapped off the valve to start with. I looked into the inflator to find the valve core stuck and completely inaccessible.

No bother I thought, must have just got frozen and stuck in there, I have another tube and I'll use my Topeak Race Rocket - this has a built in mini hose and screw-on connector. 5 mins later EXACTLY the same thing...

Ended up having to push to the nearest house, luckily someone was in, let me get out of the rain for a few minutes and lent me a pair of pliers to extract the core and tighten it up. Things could have been a lot worse.

20 years of serious cycling and this is the first time this has happened. There is definitely something about the design of these Conti tubes that makes this happen - you really need to torque-on the pump head to get a good seal and I guess that this contributes to unscrewing the valve on the way back off.

Personally, I don't expect to have to buy locktite, I just expect tubes (especially 'premium' ones) to work!

MikeDee
Posts: 569
Joined: 11 Dec 2014, 8:36pm

Re: Has something changed in tyre valves?

Postby MikeDee » 9 Jun 2018, 4:12pm

Brucey wrote:somewhere between 1/10 and 1/4 of the punctures that I have had in recent years have gashed the tyre badly enough that a tube would have to be fitted to a tubeless tyre and a boot is needed with any tyre. It is easy enough to make the tyre rideable again with tubed tyres, rather less so with tubeless. I am not looking to change to tubeless anytime soon...

cheers


People are having good luck with plug kits like this https://www.amazon.com/Genuine-Innovati ... B01MG5LGCM. No need to even remove the tire from the rim. I've got one on order. YMMV

MikeDee
Posts: 569
Joined: 11 Dec 2014, 8:36pm

Re: Has something changed in tyre valves?

Postby MikeDee » 9 Jun 2018, 9:46pm

RickH wrote:
Roadster wrote:The connectors on Lezyne mini-pumps are notorious for unscrewing presta valve cores upon removal, causing instant deflation of the tube after one has just expended significant time and energy on pumping it up. If you've recently bought such a pump and haven't yet used it, check that your removable valve cores (if fitted) are well tight before you do. Don't ask me how I know this...!

The newer connectors with a pressure release button (to depressurise the hose) are supposed to help stop the adapter unscrewing the core.

I've not encountered any problem with cores unscrewing using mine (but I do also habitually check the core is tight when first using a tube).

A recent foray into tubeless tyre territory means I now have a tool specifically for the job of tightening (& removing) valve cores that I've added to my on-the-road toolkit.

DSC_0574_crop_219x309.JPG


Be careful with that plastic tool. If the valve core is too tight, the tool rounds out. I purchased a metal one after having the problem.

ratherbeintobago
Posts: 280
Joined: 5 Dec 2010, 6:31pm

Re: Has something changed in tyre valves?

Postby ratherbeintobago » 9 Jun 2018, 9:51pm

I have both a Stan’s valve core tool (aluminium) and a Unior 4mm spanner.

Brucey
Posts: 34312
Joined: 4 Jan 2012, 6:25pm

Re: Has something changed in tyre valves?

Postby Brucey » 9 Jun 2018, 11:39pm

MikeDee wrote:
People are having good luck with plug kits like this https://www.amazon.com/Genuine-Innovati ... B01MG5LGCM. No need to even remove the tire from the rim. I've got one on order. YMMV


sure, you have a pretty fair chance of making a repair this way, but only to punctures that are relatively small (think flints and big thorns, the kind of thing that ought to seal with the sealant, but won't quite). Anything where you would be thinking 'boot' with a tubed tyre, and it ain't gonna work; the carcass itself needs help and the plug won't seal.

Emergency tubeless repair kits for motorcycles and cars work the same way; the bicycle kit looks like a "doll's house" version of that.

BTW if you want a cheapskate's version of a tubeless repair kit, a handle attached to a decent sized sewing needle (so the eye end is the working end) and some plugs made from strips cut from an old inner tube might work. These can be bonded in place with rubber solution, and trimmed flush once the adhesive has set.

cheers
-------------------------------------------------------------------------------
~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~