Tyre pressure query

in message <[email hidden]>, Judith

(') said:

I have just bought and fitted a new tyre for my back wheel.

The wheel size is 26 x 1 3/8 and the bike is a commuter/road type.

Although both my old and my new tyres appear to be made by the same
manufacturer (Vee Rubber), and are identical apart from the wall
colour, I notice that the old one said inflate to 65 psi and the new
one says inflate to only 44 psi.

I'm sure I should be able to work out the science of this but I can't!
Can I infer that the new tyre is "better"? It certainly makes it
easier to inflate - I can now get it almost up to pressure using my
hand pump.

No, possibly worse. Better tyres can take higher pressures. But the
probability is they're much the same and the manufacturer of the newere
tyre is just being cautious. If you're riding on road 65 or more is
going to be better; on soft surfaces 40 is going to be better because
you get a bigger contact patch.

But you're most unlikely to have trouble even with a poor quality tyre at
65psi.

Quoted message said:

A second question: I've had a lot of trouble trying to buy a 26 x 1
3/8 inner tube with a car-type valve. In fact, I've had to buy one
with a Presta valve. I'm not too bothered - I do have a Presta
adapter for my pump - but I wondered why they had disappeared from the
shelves. I didn't think to ask the man in the LBS because I didn't
even notice till I got home!

You can certainly still get shraeder valve 26" tubes - indeed, at 26",
shraeder is probably the default.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

Due to financial constraints, the light at the end of the tunnel
has been switched off.

In message <[email hidden]>

Judith said:

A second question: I've had a lot of trouble trying to buy a 26 x 1
3/8 inner tube with a car-type valve. In fact, I've had to buy one
with a Presta valve. I'm not too bothered - I do have a Presta
adapter for my pump - but I wondered why they had disappeared from the
shelves. I didn't think to ask the man in the LBS because I didn't
even notice till I got home!

If you have not fitted the tube, take it back.

It would be wise for someone else to confirm, but I think that you can
use larger tube cross-sections than the tyre size. e.g. 26 x 1/2.
but *not* 27 x 3/8

The presta adapter for a pervious pump I had did not work well, and leaked.
They are small and easy to loose, so it is probably best to buy a
shreader valved tube next time.

Martin.

--
According to the human genome project, humans are 50-60% bananas.
When emailing me, please include the word Banana in the subject line.

On 07/18/2005 02:58:31 Martin Dann said:

In message <[email hidden]> Judith
<[email hidden]> wrote:

Quoted message said:

Quoted message said:

A second question: I've had a lot of trouble trying to buy a 26 x 1 3/8
inner tube with a car-type valve. In fact, I've had to buy one with a
Presta valve. I'm not too bothered - I do have a Presta adapter for my
pump - but I wondered why they had disappeared from the shelves. I
didn't think to ask the man in the LBS because I didn't even notice till
I got home!

Quoted message said:

If you have not fitted the tube, take it back.

Quoted message said:

It would be wise for someone else to confirm, but I think that you can use
larger tube cross-sections than the tyre size. e.g. 26 x 1/2. but *not*
27 x 3/8

Quoted message said:

The presta adapter for a pervious pump I had did not work well, and
leaked. They are small and easy to loose, so it is probably best to buy a
shreader valved tube next time.

I'm sure we list tubes of that configuration from Schwalbe.

--

Buck

I would rather be out on my Catrike

http://www.catrike.co.uk