Presta valve snapped off

[272BHP]

This has just happened twice in two days now.

Unscrewed the valve to pump the tyre up and the valve has snapped off. Today pumped up the rear tyre and the same thing happened. I haven't got time to buy a new tyre till tomorrow evening now.

Rear tyre pumped up ok before the valve sheared off so the tyre is still fully inflated - will it be ok to ride tomorrow?

[Magic919]

I presume you meant the lock nut, not the valve. I expect it'll stay up ok.

[272BHP]

Of course, yes I meant the locknut. It seems to be staying up ok so I will use it tomorrow.

Cheers

[IroningMan]

If you don't already use a track pump then it's time to get one.

[Fastpedeller]

some of the presta valves are removable by grasping the 2 tiny flats with a pair of pliers - and can then be replaced complete with the knurled end if you have a spare from an old tube.

[CoolC]

http://www.wiggle.co.uk/tufo-valve-core/?lang=en&a...

You can buy replacement cores too.

[TwistingMyMelon]

Got fed up of bending/breaking/etc presta so now always use one of these adapters and use the Scrader end of my track pump:



I always carry it with me as it extends out the valve as well if you get caught short on a ride and makes a better more sealed connection.

[Vipers]

272BHP said:

This has just happened twice in two days now.

Unscrewed the valve to pump the tyre up and the valve has snapped off. Today pumped up the rear tyre and the same thing happened. I haven't got time to buy a new tyre till tomorrow evening now.

Rear tyre pumped up ok before the valve sheared off so the tyre is still fully inflated - will it be ok to ride tomorrow?

Is it worth looking at the type of tubes you buy, I have never ever had this happen to me in over 20 years of cycling.

[stripy7]

Using the dust cap wont help, you're twisting the valve each time you undo/ do it up. Throw it away.

[TwistingMyMelon]

stripy7 said:

Using the dust cap wont help, you're twisting the valve each time you undo/ do it up. Throw it away.

Fine for summer rides, commuting through winter and uncapped valves are a liability ive found

[JustinF]

What pump are you using?
The valve cores are fragile and any sort of rigid pump that clamps onto the valve stem can damage them with 'vigorous pumping', some pumps have a little give in the end by design others not, ideally you want one with a bit of hose that attaches to remove the issue entirely.

[Bobley]

I've bent a few valve tips using an old Blackburn twist grip type fitting but my newer Lezyne track pump has never damaged the valves.

[exgtt]

Mine snapped about 2 months ago, it's fine! Not tried topping up the pressure yet but it hasn't gone down and I ride to work everyday.

[272BHP]

I use a track pump. I will just try and be a bit gentler with it I think and see how I get on.

[Clinton Baptiste]

I did exactly the same thing with my track pump the other week but it was on my turbo trainer tyre so not sorted it yet (the pressure has stayed up) . First time it's happened to me in 20 years or so of riding.

[Albert Bridge]

Happened to me last week as well whilst using a track pump. I decided not to risk it and changed the tube. No idea why it happened.