save10

I've been using 'zipp' type valve extenders without issue, except that the pressure gauge does not read. I have read that with extenders that can accept a valve core the pressure gauge will work better

I recently got vittoria valve extenders where you can removing the valve core. And I cannot get these things to hold air.

Here is what I am doing -

a) remove valve core with supplied tool
b) put a few layers of teflon tape on threaded section of valve extender and install it on to the tire using tool provided
c) put a few layers of teflon tape on threaded section of valve core and install it into the valve extender with tool provided.
d) remount tire as before (tubular w/o glue - just in the prestretching process)
e) inflate as usual
f) curse to no one in particular that it wont hold air

I have tried varying amounts of teflon tape to no avail. I also was concerned that i had some how damaged the valve core when I removed them. So I re-installed the valve cores into the tires then put back the zipp extenders and remounted. held air as before.

What am I doing wrong here? thnx.