Valve extenders

I've been tearing my hair lately over valve extenders failing to keep tight at pressures over 80. I'm using the vittoria tubulars that comes with a removable valve, wich seems to be fine. But coupled with an extender, in my case toepak it all goes to shit as soon as i start getting pressure up. Its gone to the point where I have to employ a second pair of hands just to press the extender down to the vittoria vale while pumping.

Does anyone have experience with this or alternative extenders that work with vittoria. Seeing how the vittoria evo cx's are one of the most commonly i'm expecting more people to have problems like this when fitting them to a deep rim.

Can't remember brand of extender, but v similar to topeak with plastic sleeve at end I think.

Used a bit of thread lock on installation to conti sprinter.

Never had issue to 100psi.

so is it the pump end that is blowing off the extender when pressure goes about 80psi?

I used to have this issue, its to do with the pump end not being able to bite onto the extender properly. I figured out a neat trick to make it hold properly, although it depends what type of pump you have.

The end of mine looks like this:

What i do is unscrew the grey bit off the end and there is a rubber ring inside it. Slide them over the extender so the rubber ring is on it well. Screw it back together on the extender and pump away. You can pull it off when you are done in the usual manner.

Sounds complicated, its not, takes 30 seconds.

aah yeah thats the fucker i use. Ill give it a shot tonight. thanks a bunch!

Maybe try a Vittoria extender? Or plumbers tape between the extender and the normal valve (not for the internal ones).

I use Topeak extenders with the twisty bit in the middle that lets you operate the normal valve.

Sorry- to be clear, is the pump head pushing itself off the top of the valve extender, or is the valve extender coming loose from the tub?

Sorry- to be clear, is the pump head pushing itself off the top of the valve extender, or is the valve extender coming loose from the tub?

its the toepak extenders leaving a bit of a gap to the vittoria valve. the mechanism itself works but the outer shell is not airtight on high pressures.

Tried taping it up with duct tape but it wont hold over 80psi either.

Guess ill try my luck with vittoria extenders then. Getting a bit tired of reglueing tubes.

Oh i see, i thought your issue was with the pump blowing off the extender.

I have vittoria tubs and use the BBB extenders http://www.wiggle.co.uk/bbb-bti-97-valve-extension-50mm/

I installed them without ripping the tub off. Just wrapped a bit of ptfe tape around the outside and poked it inside, made a hole with a biro and screwed it in. Worked a treat.

Nice thing about those extenders is the external screw thread. Lets you use a hand pump such as the Lezynes which screw on.

here is the culprit. the extender screws on loosely and then snaps back a thread instead of snuggling up tight. I got two and they both behave the same way.

Sounds like the thread is goosed. But have you used PTFE tape to create a seal?

How are the internal threads on the extender? The first one of those I used disintergrated straight away...

^^ what hovis said...

yeah threads are definitely gone on these plastic crap extenders. Ill give tape a try and then its an aluminium extender : /

thanks folks!

http://www.youtube.com/watch?v=02jwDe5f3Hg

yeah threads are definitely gone on these plastic crap extenders. Ill give tape a try and then its an aluminium extender : /
thanks folks!

I thought those Topeaks were alu? Mine are quite a bit longer though.

I hate to say this, but have you considered using the correct length Vittoria valve extender?

I've used them- they are annoyingly expensive but they work perfectly.

The entire red "valve" assembly unscrews from the tub, then just screw on the correct length for your rim ,and hey presto.

The entire red "valve" assembly unscrews from the tub, then just screw on the correct length for your rim ,and hey presto.

yeah im looking at them and scoffing at the median price of ~20 for the pair. nuts.

get the BBB ones i posted. They work perfectly and are dirt cheap

I thought those Topeaks were alu? Mine are quite a bit longer though.

Same here. Never had a problem with Topeaks, I like the silver insert they have allowing you to open and close the valve if the valve is recessed. I found that Conti brass extenders sometimes needed a small rubber o-ring, they don't last long though if you're removing the extender every time you use the wheel

Lost mine in my rim and tried a YouTube
method of removal - no dice. Just tried the 5th bike shop in the City but no one could help - any alternative knowledge/tips?

OK, I finally got it out after over an hour of swearing and a paper clip. I learnt that:

• it's easier to get it out of the nipple side of the rim rather than the rim tape side (if that makes sense),
  
• a paper clip through the larger end of the extender is the only side that you can feasibly pick at,
  
• guiding it whilst looking through the valve hole from above was the easiest tactic.
  
  

Panic over. Am unimpressed that Evans and Cyclesurgery (no closer LBS to my work I'm afraid) either didn't have mechanics available or couldn't take on the job.