Re: [CR] "Classsic" 700C Presta valve inner tubes

From: "David Snyder" <dddd@pacbell.net>
To: <classicrendezvous@bikelist.org>
References: <001501caee1e$325a51d0$970ef570$@cox.net> <4BE4726A.7090604@m-gineering.nl> <363746F9BAC548798E29CAC82C295A77@ARSPC> <4BE50244.8000000@m-gineering.nl> <AANLkTin1lffae5proEG-GIkiTBFoejrXDZw2do_RrrCb@mail.gmail.com> <4C080456.8020202@aol.com> <4C0EA782.1030101@os2.dhs.org>
In-Reply-To: <4C0EA782.1030101@os2.dhs.org>
Date: Tue, 8 Jun 2010 13:54:46 -0700
Subject: Re: [CR] "Classsic" 700C Presta valve inner tubes

All presta valves are threaded. The smaller-diameter cap threads are the only part of the valve that the pump gasket is supposed to engage.

Once the gasket is forced onto the larger diameter threaded (or un-threaded) portion of the stem, damage occurs to the gasket and it may no longer seal properly on the cap threads. This applies to push-on pump heads and lock-on (lever operated) pump heads. I have yet to find an exception, but most presta heads do get reamed out eventually by improper use.

Some of today's mini-pumps won't seal onto the stems with wrench flats (for valve-core removal). These same pumps won't fit onto the larger diameter of the stem either, even if forced.

David Snyder
Auburn, CA usa

----- Original Message -----

Subject: Re: [CR] "Classsic" 700C Presta valve inner tubes
>
> I've come to dislike threaded tube stems because they shred my pump
> gaskets.
>
> -John Thompson (john@os2.dhs.org)
> Appleton WI USA