The solution is very simple. Get rid of those terrible valve extenders. They are going to be nothing but trouble.

Sorry, you are going to have to remove the tire to do this.

Get valve extenders that require you to remove the valve core from the tire, insert the extender, and reinstall the valve into the extender. Everything will then work the same as every other tire.

Oh, yeah. Through the Zipp extenders in the trash.

I use Tufo's valve extender. Instead of keeping the presta valve open and screwing on an extender, you actually remove the valve core, screw the extender into the exposed valve (with some teflon tape, just in case) and reinstall the core. You now have a valve that's several inches longer and you can open and close the valve normally. Obviosuly, you have to remove the tire to perform this minor surgery.

Visit the Tufo web site for details. You can get the valve extenders online fairly inexpensively. If you need to replace the tunular, just remember to take off the extender before tossing the tire.

ok, several things. what kind of tubulars do you have? and do they have removable valve stems? some do, some dont.

i think i can help you, but i have very successfully used zipp valve extenders with clincher tubes, whose main difference is that they typically do not have removable valve stems. otherwise the principal should be the same with your tubulars.

you have an interesting and very strange pump problem. these are floor pumps, yes? can you post a link that shows an image of your pump(s) (from an online catalog or something)?

it seems that if we can solve your pump problem, then you can safely set up your zipp extenders correctly, so lets focus on the pump issue first. i have used with zipp extenders with silca track pumps and a topeak "sprint" floor pumps, but there are many others that will work.

answer q's above if you can...

more to come after that.

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Where would you want to swim ?

if you toss zipp extenders in the trash, can you send them to me instead?

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Where would you want to swim ?

Actually, I think I have some from my 303's. You are welcome to them.

Hmm - I've never had any problems in several years of using these. Did you core out the valve as per instructions? Tighten the extender with a hex wrench?

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Fatigue is biochemical, not biomechanical.
- Andrew Coggan, PhD

I second the earlier recommendation for Tufo's. I think their tires are the best tubulars on the market and the ability to lengthen the valves is the best solution for deep rims. They're pricey but well worth it.

<<what kind of tubulars do you have?>>

vittoria corsa evo cx...don't know about the way the presta valve works...but i am certain someone on the forum knows since they are common high performace tubulars

<<you have an interesting and very strange pump problem. these are floor pumps, yes? can you post a link that shows an image of your pump(s) (from an online catalog or something)? >>

the pump issue is very stange...here is a photo



http://www.bikesomewhere.com/...tLarge/206/1373/3746



thanks for your help...

Vittoria also makes extenders that replace your valve core. Since you have Vittoria tubulars, they do have the removable valve core. I also suggest going with extenders that replace your valve core and move it to the end of the extender.

The only problem with the Vittoria extenders is that they are just barely long enough to get the job done on a set of 404s. My solution was to use a presta to schrader adapter and then attaching my pump to the adapter. (This is just used for tire inflation purposes of course.)

same pump as a friend of mine, eats her Zipp extenders as well. But with a little teflon tape and a 1/4 turn to tighten them on using a pair of plyers and they shouldn't loosen up. I personally use the removable core valve extenders. They are barely long enough on my 404 tubulars

To go off on a bit of a tangent, I use the 404 clinchers (tubie-purists insert "boos" here), but have had the same type of frustration with those extenders. I've been looking for a while for tubes with a long enough stem to not necessitate using the extenders, but haven't had any luck - until recently when I found that Vredestein makes a tube with an 80mm stem - I just bought a supply of them off excelsports.

i have had zero problems with zipp valve extenders, when installed correctly. they are simple, cheap, and very light.

so, on to your problems:

1 - it appears you have figured this out, but i'll review: open the valve on your tire or tube until the the little cap nut stops moving. take a pair of pliers and carefully "force" the nut past this point by about 1/4 turn or a little more (this locks the valve and prevents it from closing on its own from vibration). then apply a bunch of layers (4 to 5 times around at least) of carefully double-folded (folded because otherwise it is very thin and too wide for the small valve) teflon plumber's tape around the upper threads of the valve stem, being careful not to block the air entry area of the tire/tube with the wrapped tape. then screw on the black zipp valve extender. tighten it fully by inserting and allen wrench into the end of the extender (it is machined to fit one exactly) and snug it on as best you can.

the teflon tape has 2 functions: it seals the extender, preventing air from escaping as you fill it, and it keeps the extender from slowly working its way off the valve, by giving the threads something soft to bite into. with the valve stem open all the time, the valve seals itself (when it is not being filled with air) because air pressure inside the tire keeps it closed tightly--so there is no need to screw it down. sadly, doing all these steps for tubular tires requires that the tire be removed from your rims--a big job.


2 - there is something strange about your pumps. for typical floor pumps, they slip over the presta valve (or slip over the presta valve extender) and then there is a lever that you flip to lock the pump head over the tire valve. then you unflip the the lever to remove the pump head off the valve when you are done pumping the tire. but you seem to say that even unlocked your blackburn pumps are very tight over your zipp extenders. so when you are struggling with your pump, you have remembered to unlock the pump head, right? because if your pump is super tight even with the head unlocked, this is a big problem and may require a new floor pump. if it were me, i would go over to the shop where i bought these crazy pumps, show them this problem, and ask the folks there if these pumps are supposed to do this and what they recommend to solve this big problem. ask for a pump exchange.

there is another type of floor pump that does not have a lock, but simply fits very tightly over all valves and extenders. a typical example of these is the silca floor pumps. they fit quite tightly on the extenders, but still work adequately, although you have to wrestle with them a bit. if you replace one of your pumps, i think you will have better luck with a pump with a locking head, not one of these silca pumps.

in any case, you should never have to remove the extender once you install it unless you are tossing the tube or tire. you should never have to take the extender off to get the pump off.

3 - about pump recommendations, there are many that will work. but if you go back to your bike shop and return your crappy blackburn one, get another one that will work as i have described. and you will know this because you will take one of your spare tires with a zipp valve extender installed and you will test it in the shop to check that it works flawlessly.

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Where would you want to swim ?