tube size and mtb tyres

Al M said:

Sorry if these are dumb questions but I've not been cycling since my
old Peugeot 10speed about 20 years ago, so I have some catching up to
do.

How critical is tube size?

Not very.

Quoted message said:

My Giant mtb came new with 26x1.75 knobbly
tyres and I want to change to a slick tyre, maybe 26x1.5. Can I use my
existing tubes with the skinnier tyres? (The tubes are marked 1.9.
They also have Presta valves if that makes a difference?

Every tube I've seen is marked with a range, not just one size. Look for
another number as well the 1.9.

A tube can be used with tyre narrower than it's designed for but it might be
harder/weirder to fit, as well as weighing more than necessary.

Quoted message said:

BTW, I'm considering the slick tyre as my riding is mainly tarmac
roads with some packed gravel forest tracks, no mud. I'm not choosing
semi-slicks because I think they won't be any better on tarmac
corners than my knobbly tyres (which tend to slide). Does this theory
sound okay?

Sounds good to me.

~PB

in message <[email hidden]>, Al M

(') said:

Sorry if these are dumb questions but I've not been cycling since my
old Peugeot 10speed about 20 years ago, so I have some catching up to
do.

How critical is tube size? My Giant mtb came new with 26x1.75 knobbly
tyres and I want to change to a slick tyre, maybe 26x1.5. Can I use my
existing tubes with the skinnier tyres? (The tubes are marked 1.9.
They also have Presta valves if that makes a difference?

You can use your old tubes with the new tyres. Tubes are pretty adaptable,
because they stretch like balloons. However, if you use skinnier tubes in
fatter tyres, they do become a bit more vulnerable to punctures, because
they get thinner. Obvious, really.

Quoted message said:

BTW, I'm considering the slick tyre as my riding is mainly tarmac
roads with some packed gravel forest tracks, no mud. I'm not choosing
semi-slicks because I think they won't be any better on tarmac
corners than my knobbly tyres (which tend to slide). Does this theory
sound okay?

Slicks are really, really good on tarmac and really, really bad on soft mud
or clay. If your routes involve soft mud or clay I'd strongly advise
against slicks - you'll fall and it will hurt. On well packed gravel
tracks slicks will be fine.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/
There's nae Gods, an there's precious few heroes
but there's plenty on the dole in th Land o th Leal;
And it's time now, tae sweep the future clear o
th lies o a past that we know wis never real.

Al M said:

Sorry if these are dumb questions but I've not been cycling since my
old Peugeot 10speed about 20 years ago, so I have some catching up to
do.

How critical is tube size? My Giant mtb came new with 26x1.75 knobbly
tyres and I want to change to a slick tyre, maybe 26x1.5. Can I use my
existing tubes with the skinnier tyres? (The tubes are marked 1.9.
They also have Presta valves if that makes a difference?

Schwalbe have some useful info at http://www.schwalbe.de/gbl/en/bicycle/tubes/

In article <[email hidden]>, Al M
[email hidden] says...

Quoted message said:

Sorry if these are dumb questions but I've not been cycling since my
old Peugeot 10speed about 20 years ago, so I have some catching up to
do.

How critical is tube size? My Giant mtb came new with 26x1.75 knobbly
tyres and I want to change to a slick tyre, maybe 26x1.5. Can I use my
existing tubes with the skinnier tyres? (The tubes are marked 1.9.
They also have Presta valves if that makes a difference?

Take one of the tubes, inflate it just enough to hold its shape and
place it inside one of the tyres (off the rim). Now look across the
tyre beads - if the tube isn't sticking out past the bead then it will
be fine, if it sticks out a bit you might get away with it but it will
probably be tricky to fit.

Quoted message said:

BTW, I'm considering the slick tyre as my riding is mainly tarmac
roads with some packed gravel forest tracks, no mud. I'm not choosing
semi-slicks because I think they won't be any better on tarmac
corners than my knobbly tyres (which tend to slide). Does this theory
sound okay?

I'd be inclined to go for something like a Specialized Nimbus, which is
effectively a grooved slick, but that's probably just a personal
prejudice.

"Al M" <[email hidden]> wrote

Quoted message said:

BTW, I'm considering the slick tyre as my riding is mainly tarmac
roads with some packed gravel forest tracks, no mud. I'm not choosing
semi-slicks because I think they won't be any better on tarmac
corners than my knobbly tyres (which tend to slide). Does this theory
sound okay?

I would suggest semi slicks are worse on tarmac than knobblies because they
*don't* slide - before letting go very suddenly. "Slicks" will transform
the feel of the bike.

You could try
http://www.wiggle.co.uk/ProductDetail.aspx?Cat=cycle&ProdID=5300003782

in the 1.25 inch width though these do need smaller tubes. They are really
intended as touring tyres and I reckon to ride at least two gears higher
than on knobblies. But I have no particular qualms about using them
anywhere I won't get dirty.

DavidR said:

"Al M" <[email hidden]> wrote

Quoted message said:

BTW, I'm considering the slick tyre as my riding is mainly tarmac
roads with some packed gravel forest tracks, no mud. I'm not choosing
semi-slicks because I think they won't be any better on tarmac
corners than my knobbly tyres (which tend to slide). Does this theory
sound okay?

I would suggest semi slicks are worse on tarmac than knobblies because they
*don't* slide - before letting go very suddenly. "Slicks" will transform
the feel of the bike.

You could tryhttp://www.wiggle.co.uk/ProductDetail.aspx?Cat=cycle&ProdID=5300003782

in the 1.25 inch width though these do need smaller tubes. They are really
intended as touring tyres and I reckon to ride at least two gears higher
than on knobblies. But I have no particular qualms about using them
anywhere I won't get dirty.

Thanks for the help guys. I checked again and the tubes say 1.9/2.125,
which sound wide but I put inside my new 1.5 slicks and they fitted
okay. I just paid extra making sure not to nip the tubes as I started
inflating them. Will probably buy some smaller ones soon.
Al