Wor

Doki said:

Back on the bike for the first time in ages. 10 minutes down to uni and
15 back. With 2 flat tyres...

If it's been a while, you may not remember, but you're supposed to
inflate them ;-)

--
Brian G
www.wetwo.co.uk

"Brian G" <[email hidden]> wrote in message
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Quoted message said:

Doki said:

Back on the bike for the first time in ages. 10 minutes down to uni and
15 back. With 2 flat tyres...

If it's been a while, you may not remember, but you're supposed to inflate
them ;-)

I think they must have decided to deflate themselves over the past month or
two. Still, not a bad time considering the extra rolling resistance and my
general state of knackerage 😉.

"Doki" <[email hidden]> wrote in message
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Quoted message said:

"Brian G" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Doki said:

Back on the bike for the first time in ages. 10 minutes down to uni and
15 back. With 2 flat tyres...

If it's been a while, you may not remember, but you're supposed to
inflate them ;-)

I think they must have decided to deflate themselves over the past month
or two. Still, not a bad time considering the extra rolling resistance and
my general state of knackerage 😉.

You have probably also damaged the tyres / inner tubes.

In article <[email hidden]>, Doki
[email hidden] says...

Quoted message said:

"Brian G" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Doki said:

Back on the bike for the first time in ages. 10 minutes down to uni and
15 back. With 2 flat tyres...

If it's been a while, you may not remember, but you're supposed to inflate
them ;-)

I think they must have decided to deflate themselves over the past month or
two.

They tend to do that.

Quoted message said:

Still, not a bad time considering the extra rolling resistance and my
general state of knackerage 😉.

Do you not at least give your tyres a quick squeeze as a basic pressure
check if you haven't used the bike for a few days?

Rob Morley said:

Do you not at least give your tyres a quick squeeze as a basic pressure
check if you haven't used the bike for a few days?

A few weeks more like. After which time I've started noticing it's a
bit harder going, but I don't think they've ever got below 60 psi on the
'bent or the Brom, which is still fine for almost all roadgoing purposes.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch said:

Rob Morley said:

Do you not at least give your tyres a quick squeeze as a basic pressure
check if you haven't used the bike for a few days?

A few weeks more like. After which time I've started noticing it's a
bit harder going, but I don't think they've ever got below 60 psi on the
'bent or the Brom, which is still fine for almost all roadgoing purposes.

Pete.

my road going mountain bike does loose pressure fairly quickly, but then
i run the tires at 100 psi, so after a few days does get softer.

would there be any advantage or disadantages to using presta valves
compared to Schrader particuly as my rims are Schrader drilled?

roger

In article <[email hidden]>, Roger
Merriman
[email hidden] says...

Quoted message said:

my road going mountain bike does loose pressure fairly quickly, but then
i run the tires at 100 psi, so after a few days does get softer.

would there be any advantage or disadantages to using presta valves
compared to Schrader particuly as my rims are Schrader drilled?

Theoretically a schrader valve may open slightly when the wheel rotates
fast as the valve core is thrown outwards by centrifugal force, while a
presta valve is held shut by its locknut, but IRL I think the combined
pressure of the spring and air should be enough to prevent this. In any
case a good valve cap (metal with a rubber washer) will prevent air
loss. Schrader valves seem to lose more air when fitting/removing the
pump connector, and presta valves fit better on very narrow rims.
Schrader has the advantage of a replaceable core (but the disadvantage
that the core may be loose!) while presta locknuts are vulnerable to
being snapped off. I reckon it's case of swings and roundabouts
really.

On the subject of rim drilling, if you want to fit a presta valve in a
schrader-drilled rim you can fit a grommet to take up the slack, but
I've never bothered, in fact I think it's useful to have extra slack
around the valve so you can see if the tube is moving relative to the
rim. If you're the sort of person who regularly ploughs through deep
mud or water then grommets may help to keep some of the crud out of box
section rims.

Rob Morley said:

In article <[email hidden]>, Roger
Merriman
[email hidden] says...

Quoted message said:

my road going mountain bike does loose pressure fairly quickly, but then
i run the tires at 100 psi, so after a few days does get softer.

would there be any advantage or disadantages to using presta valves
compared to Schrader particuly as my rims are Schrader drilled?

Theoretically a schrader valve may open slightly when the wheel rotates
fast as the valve core is thrown outwards by centrifugal force, while a
presta valve is held shut by its locknut, but IRL I think the combined
pressure of the spring and air should be enough to prevent this. In any
case a good valve cap (metal with a rubber washer) will prevent air
loss. Schrader valves seem to lose more air when fitting/removing the
pump connector, and presta valves fit better on very narrow rims.
Schrader has the advantage of a replaceable core (but the disadvantage
that the core may be loose!) while presta locknuts are vulnerable to
being snapped off. I reckon it's case of swings and roundabouts
really.

On the subject of rim drilling, if you want to fit a presta valve in a
schrader-drilled rim you can fit a grommet to take up the slack, but
I've never bothered, in fact I think it's useful to have extra slack
around the valve so you can see if the tube is moving relative to the
rim. If you're the sort of person who regularly ploughs through deep
mud or water then grommets may help to keep some of the crud out of box
section rims.

okay well it's a old mountain bike with road tires, i had woundered if
at the high pressures might puncture around the drill hole.

i do prefer presta, so i'll get some fitted, should help the fitting as
well being smaller there is slight bulge there.

roger

In article <[email hidden]>, Roger
Merriman
[email hidden] says...

Quoted message said:

okay well it's a old mountain bike with road tires, i had woundered if
at the high pressures might puncture around the drill hole.

As long as there isn't a sharp edge on the inside of the valve hole it
shouldn't be a problem.

Quoted message said:

i do prefer presta, so i'll get some fitted, should help the fitting as
well being smaller there is slight bulge there.

If the valve stem is causing a bulge in the tyre then the tube isn't
fitted correctly - partially deflate it then push the valve in and
massage the tyre bead onto its seat.

Rob Morley said:

In article <[email hidden]>, Roger
Merriman
[email hidden] says...

Quoted message said:

okay well it's a old mountain bike with road tires, i had woundered if
at the high pressures might puncture around the drill hole.

As long as there isn't a sharp edge on the inside of the valve hole it
shouldn't be a problem.

Quoted message said:

ok good to know.

Quoted message said:

Quoted message said:

i do prefer presta, so i'll get some fitted, should help the fitting as
well being smaller there is slight bulge there.

If the valve stem is causing a bulge in the tyre then the tube isn't
fitted correctly - partially deflate it then push the valve in and
massage the tyre bead onto its seat.

looking again the bulge has gone i guess the last ride let the tire/tube
find it's place. it's bloody tight on, even the bike shop mentioned
that. so a presta tube should allow more room.

roger