New Wheels with Valve extenders- don't stay pumped up...

Hi,

Tubulars all have Latex tubes sewn up inside them, so they will naturally lose air pressure considerably quicker than a butyl tube would. It's possible the Valve extender is contributing (most people just screw the extender on the end and leave the valve core itself in the open position as opposed to removing the core and screwing it into the top of the extender) but most latex tubes will lose enough air that they will need to be inflated before every ride.

Also no, you'll need to remove and re-glue the tires to get to the valve.

You've probably seen the article I linked in below. It tells you everything you could ever want to know about valve extenders.

http://www.slowtwitch.com/Tech/Valve_Extender_How-To_3007.html

Are you dealing with a removable core style extender? If not, the "seals" really don't matter because the extender only sees pressure when you're pumping the tire. It doesn't hold any pressure when you're riding.

If you have a removable core relocated to the end of your extender, you should be able to remove it and reseal it without removing the tire, but I wouldn't recommend removing the extender from the tire stem itself to reseal that joint unless you're prepared to remove the entire tire.

However, I second the above comments about latex. I ride latex clincher tubes pretty regularly, and my tire pressure will drop substantially overnight. This is all about the tube material and very likely has nothing to do with the extenders.

Not all tubulars have latex inner tubes.

Yes, you will need to remove the tire or at least a good sized section of it to dissemble the valve and apply Teflon tape. While there put some electrical tape around the valve so it does not chatter against the inside of the wheel.

There is some confusion here.
Ok, you have tubular tires on these wheels. But you're not sure if they have latex tubes. So let's narrow this down:

If your tires do have latex tubes inside, then, yes, you will need to top them off with air every day that you ride (even if there are no leaks from valve stems or other places). But if they have the more common butyl tubes inside, then you do not have to inflate them very regularly (i.e., no more or less than typical bike tubes/tires).

Valve extenders:
If you have the more common 'tube' type valve extenders (these are essentially hollow tubes that just screw on to your valves, like those sold by zipp and many others), then teflon tape won't really affect your leaking issue.

Yes, you still should use teflon tape on these type of extenders (we use these type of extenders and use teflon tape on all of them). If you fail to use teflon tape on them, then during inflation they will indeed leak from the extender/valve gap *while* you're pumping. You still might be able to fill them (it will take you a lot longer), but they won't leak *after* you're finished with the inflation process.

However, if you have less common 'removable core' type valve extenders (these are extenders that require you to remove the valve from your tube), then teflon tape will absolutely affect your leaking issue. If fail to seal these with teflon tape, there will be a leak between the extender/valve gap all of the time. Your tires will not hold air for any duration.

(A bit off topic, for this reason, the hollow valve extenders are more fail safe. If they fail, yes, you'll have some trouble during filling, but otherwise the tubes will still hold air. But if removable core valve extenders fail, you will lose air immediately, you won't even be able to ride.)

Hope that helps,
Greg @ dsw

ok... all the good tubulars