Inflating Presta threaded valve tubes - a tip.

[rrarider]

I've been successfully using Vittoria Ultralite 700c 19-23 tubes with a threaded Presta valve and a round locking collar for some time now. Whilst testing a new head for my track pump, I deflated both 25 mm tyres, did up the locking collar finger tight only and inflated both to the maximum recommended pressure as normal.

The net result was that both tubes were irreparably damaged, as the rubber round the valve base was torn and leaked air. At the risk of publicising my own stupidity, I advise readers not to tighten the little round collar when inflating from flat. Both tubes were not just punctured, they were ruined.

 

[Cycleops]

In fact you can leave them off completely.

 

[Ian H]

The lock-ring is the bit I always throw away. They were useful as spacers for toe-clips in the old days, but I haven't found much use for them recently.

 

[I like Skol]

Or do as most people do and throw away the unnecessary locking collar. In fact I try to buy tubes with unthreaded valves where possible, much tidier and the pumps get a better seal without damaging the rubber.

I doubt the damage was due to doing up the collar, must be something else at play here.

EDIT: I'm too slow, beaten by two other posts.....

 

[rrarider]

I doubt the damage was due to doing up the collar, must be something else at play here.

Well, you're wrong, because it was.

 

[Nigel-YZ1]

That's someting I've never thought about. I usually just nip up the lock ring after inflating but never tighten as I though it would stop the valve moving about and causing damage.
That's my lesson for today!

 

[I like Skol]

Well, you're wrong, because it was.

So the tubes were already in use, you deflated them, nipped up the locknut and re-inflated exactly as you had done previously, except used a new pump and this time the tubes failed.

It appears the thing at play would be the new pump as you have done the same thing previously with the old pump and not suffered the problem.

 

[fossyant]

The locking nut causes more problems than they fix.

 

[Ian H]

Tightening the lock-ring can pull the tube down into the well. With a narrow rim the tube will be tightly wedged between the beads by the valve stem. On inflation it will try to pull away from the valve, or push the tyre away from the rim. Either way, it's likely to go pop.

 

[Salty seadog]

I always use the lock rings and nothing bad has happened to me ... yet.

On the other hand, I can't claim that they have actually made my life better.

Rotational mass....

 

[youngoldbloke]

Throw them away, and the dust caps too - you'll go a lot faster once youve got rid of all that surplus weight .
I much prefer unthreaded valves too - I use Michelin Airxxxx tubes. Less wear on push-on chucks too

 

[glasgowcyclist]

I keep the locking collar on the valve but about 1-2mm away from the rim. I find, when inflating the tyre from flat or very low, that it stops the valve from disappearing inside the rim when attaching the pump head.

And I keep the dust caps on too: I've previously run my rear without one and the salt & grit from the roads caused the little barrel to seize solid. When I tried to undo it, it wouldn't budge so I couldn't top up the pressure. When I tried to gently ease it off with a pair of long-nose pliers the valve core snapped instead.

 

[Ajax Bay]

The net result was that both tubes were irreparably damaged, as the rubber round the valve base was torn and leaked air.

How did the presence of the finger tight lockring cause the damage (or increase the risk of damage) please?

 

[Smokin Joe]

Lock rings and collars go straight in the bin. Surplus crap.

 

[Venod]

Top tip.

Don't bin the locking collars if your running tubeless.