[Yak] Re: Yak Digest, Vol 15, Issue 1

[John S. Allen]

At 01:47 PM 9/1/2005, Rob Snyder wrote:

>Virtually eliminated by having a pump with a hose!

But portable pumps these days don't have hoses. Only floor pumps do.

>More at the bottom.
>
> >
> > The tube, and my pride, deflated suddenly when the pump wiggled the
> > valve
> > stem and the rim cut through the inner tube right next to the valve
> > hole
> > where it can't be patched.

>I am starting to wonder why I have presta valves anyway, it certainly
>is not to save .5g on a 30lb recumbent with a 20lb overweight rider.

There is a good reason unrelated to weight, though it might not apply on 
your bike: a narrow rim may not be able to accommodate a Schraeder valve. 
Another reason is that the Presta valve seals without the need for a 
spring. The whole syndrome of hoseless thumblock pumps with the head 
integrated into the barrel more or less got started (with the Zéfal HP 
pump, some 30 years ago) because this works much better with the 
*Schraeder* valve. A frame pump with a hose always leaked air out of the 
tire when unscrewing the hose from a Schraeder valve. It worked OK with a 
Presta valve.

In my opinion, many inner tubes just don't have enough reinforcement around 
the valve stem. I've had Schraeder tubes fail there too.

John S. Allen

jsallen *at* bikexprt.com (replace " *at* " with "@")

http://www.bikexprt.com/