Very basic question about rims and tyres

Tom Anderson said:

Hi again,

26-inch rims - are they basically all the same width? If so, does that
mean i can buy a tyre of any width to go on them? If not, how do i
know what widths i can buy? I've always assumed rims were a standard
size, but i've never actually had to buy new tyres before, so i've
never thought about it too hard.

Wait! Why don't i read Sheldon Brown's highly informative article [1]
on the subject? Aha - so there *are* different sizes of rim, and it
does matter.

So, what width do i have? The current gignormous knobblocalyptic
tyres say 26 x 2.00, but i assume the 2.00 refers to the tyre, since
the rims aren't two inches wide. There's nothing written on the rim
itself - it's just got bloody Decathlon branding. Well, except
'Rigida' in tiny letters - a make, but no model. A bit of googling
suggests that it might be a Sphinx:

http://www.rigida.com/eng/produits/mtb_double/sphinx_r.html

It's not a Taurus, since i don't have disc brakes. If it is a Sphinx,
it has an interior width of 16.8 mm, which according to Brown and
Boeger's table should accomodate a tyre 25-37 mm across; Rigida
themselves say 25-48 mm. The tyres actually fitted claim to be 51 mm,
which is a bit odd.

Am i on the right track here? Should i give up on buying new tyres and
just slickify my knobblies with some putty?

I didn't read all that properly, to be honest, mate, but you're probably
on the right track.

Most rims can take a wide range of tyres. First think about what type and
width of tyre you'd like. If you are prepared to take a small risk, just
buy the tyre and see what it's like for yourself. MTBers often
successfully use 1.3" and 2.2ish" tyres on the same rim, regardless of
what manufacturers or SB advise.... no, not at the same time! :-)

~PB

Tom Anderson said:

26-inch rims - are they basically all the same width?

Nope.

Quoted message said:

If so, does that
mean i can buy a tyre of any width to go on them? If not, how do i know
what widths i can buy? I've always assumed rims were a standard size, but
i've never actually had to buy new tyres before, so i've never thought
about it too hard.

Wait! Why don't i read Sheldon Brown's highly informative article [1] on
the subject? Aha - so there *are* different sizes of rim, and it does
matter.

Actually my _newest_ article is more focussed, and deals specificially
with so-calle "26 inch" rims/tyres only.

Easy to remember URL: sheldonbrown.com/26

Quoted message said:

So, what width do i have? The current gignormous knobblocalyptic tyres say
26 x 2.00, but i assume the 2.00 refers to the tyre, since the rims aren't
two inches wide. There's nothing written on the rim itself - it's just got
bloody Decathlon branding. Well, except 'Rigida' in tiny letters - a make,
but no model. A bit of googling suggests that it might be a Sphinx:

http://www.rigida.com/eng/produits/mtb_double/sphinx_r.html

It's not a Taurus, since i don't have disc brakes. If it is a Sphinx, it
has an interior width of 16.8 mm, which according to Brown and Boeger's
table should accomodate a tyre 25-37 mm across; Rigida themselves say
25-48 mm. The tyres actually fitted claim to be 51 mm, which is a bit odd.

Am i on the right track here? Should i give up on buying new tyres and
just slickify my knobblies with some putty?

Definitely go for new tyres if you're riding primarily on tarmac.

Slicks are best. See: http://sheldonbrown.com/tires

Sheldon "Bald Is Beautiful" Brown

Quoted message said:

No gods, no masters.

+---------------------------------------------------------+
| We are satisfied that there can be but little liberty |
| on earth while men worship a tyrant in heaven. |
| -- Robert Green Ingersoll |
+---------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

in message <[email hidden]>, Tom

Anderson (') said:

Hi again,

26-inch rims - are they basically all the same width?

No, they aren't.

Quoted message said:

If so, does that
mean i can buy a tyre of any width to go on them?

More or less, yes. You can't put unusually narrow tyres on unusually wide
rims but apart from that I've never had a problem.

Quoted message said:

http://www.rigida.com/eng/produits/mtb_double/sphinx_r.html

It's not a Taurus, since i don't have disc brakes. If it is a Sphinx,
it has an interior width of 16.8 mm, which according to Brown and
Boeger's table should accomodate a tyre 25-37 mm across; Rigida
themselves say 25-48 mm. The tyres actually fitted claim to be 51 mm,
which is a bit odd.

Nothing odd about it. I'm sure you could safely fit 2.3" tyres, if the
frame has clearance for them. What you couldn't fit is 20mm tyres.
Frankly, if you want slicks I'd advise 1.5"/37mm, because that's not
going to give problems with your rims and it's also not going to upset
the overall handling and look of your bike too much.

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

my other car is #<Subr-Car: #5d480>
;; This joke is not funny in emacs.

Pete Biggs said:

MTBers often
successfully use 1.3" and 2.2ish" tyres on the same rim, regardless of
what manufacturers or SB advise.... no, not at the same time! :-)

I did once fit a bike with a 700c and a 27" tyre both on the same wheel
- yes at the same time! ;-)

JimP

--
I've got a cycle helmet
I'll wear it when I like
And if they want to make me
I'll go hunting on me bike

27 Mar 2006 said:

Tom Anderson said:

26-inch rims - are they basically all the same width?

Nope.

Curses!

Quoted message said:

Quoted message said:

Wait! Why don't i read Sheldon Brown's highly informative article [1] on
the subject?

Actually my _newest_ article is more focussed, and deals specificially
with so-calle "26 inch" rims/tyres only.

Easy to remember URL: sheldonbrown.com/26

That article doesn't really deal with width, though.

Incidentally, how common are these non-559 sizes? What proportion of new
bikes are either 559 or 622? How about total bikes in existence? Is
worrying about neither-559-nor-622 sizes a bit like worrying about 10-bit
bytes?

Quoted message said:

Quoted message said:

Am i on the right track here? Should i give up on buying new tyres and
just slickify my knobblies with some putty?

Definitely go for new tyres if you're riding primarily on tarmac.

Slicks are best. See: http://sheldonbrown.com/tires

Oh, i'm a convert. And i'm making an effort to just use my front brake!

tom

--
If you think it's expensive to hire a professional to do the job, wait
until you hire an amateur. -- Red Adair

Pete Biggs said:

Tom Anderson said:

Am i on the right track here?

I didn't read all that properly, to be honest, mate, but you're probably
on the right track.

Most rims can take a wide range of tyres. First think about what type
and width of tyre you'd like. If you are prepared to take a small risk,
just buy the tyre and see what it's like for yourself. MTBers often
successfully use 1.3" and 2.2ish" tyres on the same rim, regardless of
what manufacturers or SB advise....

Music to my ears. I'm going to take Simon and Sheldon's advice this time
and shoot for 1.5" slicks. No idea which ones, though - any suggestions?
Quickly poking through Wiggle, maybe:

Continental City Contact
Specialized Nimbus Armadillo MTB 06

It's a short list because i kept to puncture-resistant ones. Is puncture
resistance any good, or just a marketing gimmick?

Quoted message said:

no, not at the same time! :-)

Shame!

tom

--
If you think it's expensive to hire a professional to do the job, wait
until you hire an amateur. -- Red Adair

Tom Anderson said:

Music to my ears. I'm going to take Simon and Sheldon's advice this
time and shoot for 1.5" slicks. No idea which ones, though - any
suggestions? Quickly poking through Wiggle, maybe:

Continental City Contact
Specialized Nimbus Armadillo MTB 06

Add Schwalbe City Jet and Specialized Nimbus EX to the list. Some worry
about the City Jet's grip but it seems average to me. Don't lean like
crazy and you'll be OK on any tyres.

Quoted message said:

It's a short list because i kept to puncture-resistant ones. Is
puncture resistance any good, or just a marketing gimmick?

Most "puncture resistance" consists of a thin layer of Kevlar under the
tread. This doesn't do much as bits of glass penetrate it quite easily.
The best protection I think is simply to have thick tread (be that slick
or not) so the smaller bits of glass/flint simply don't reach the casing.
(Tiny objects don't get pressed in deeper and deeper, IME).

City Jet and Nimbus EX have a fair depth of rubber for natural puncture
resistance, but skinny sidewalls to save adding further weight and
stiffness. Armadillo must be heavier/slower.

~PB

Tom Anderson said:

Incidentally, how common are these non-559 sizes? What proportion of
new bikes are either 559 or 622?

I would guess over 95% (for adult bikes in the UK).

Quoted message said:

How about total bikes in existence?
Is worrying about neither-559-nor-622 sizes a bit like worrying about
10-bit bytes?

You'll still see other sizes, but mostly on obviously-older bikes or bikes
with much smaller wheels. It's unusual for the size not to be marked on
either the rim or tyre. Basically, if it's a modern mountain bike, it'll
be 559.

~PB

Pete Biggs said:

Tom Anderson said:

Music to my ears. I'm going to take Simon and Sheldon's advice this
time and shoot for 1.5" slicks. No idea which ones, though - any
suggestions? Quickly poking through Wiggle, maybe:

Continental City Contact
Specialized Nimbus Armadillo MTB 06

Add Schwalbe City Jet and Specialized Nimbus EX to the list.

Done.

Quoted message said:

Some worry about the City Jet's grip but it seems average to me. Don't
lean like crazy and you'll be OK on any tyres.

In fact, the City Jet's tread looks ideal for roads - lots of lovely flat
bits of rubber to grab the tarmac.

Quoted message said:

Quoted message said:

It's a short list because i kept to puncture-resistant ones. Is
puncture resistance any good, or just a marketing gimmick?

Most "puncture resistance" consists of a thin layer of Kevlar under the
tread. This doesn't do much as bits of glass penetrate it quite easily.
The best protection I think is simply to have thick tread (be that slick
or not) so the smaller bits of glass/flint simply don't reach the
casing. (Tiny objects don't get pressed in deeper and deeper, IME).

Ah, i see. I suppose the kevlar stuff is effective against thorns and
whatnot, and so useful for offroad use, but can't handle the technological
forms of sharp thing we have in cities - is that it?

Quoted message said:

City Jet and Nimbus EX have a fair depth of rubber for natural puncture
resistance,

Plus the Speccies have FlakJacket, which as far as i can tell means it
actually has a carcass, like any other tyre. Good work getting some
marketing mileage out of that, Specialized!

Quoted message said:

but skinny sidewalls to save adding further weight and stiffness.
Armadillo must be heavier/slower.

How big a difference is it really? The EX only weighs 550ish grams to
start with, so using a pair of armadillos isn't going to add more than a
couple of hundred grams, surely? There may be bleeding-edge racers for who
that matters, but for me, it's the difference between a glass of water
before i ride home or after!

While we're here, is Nimbus different to Nimbus EX? As in:

http://www.wiggle.co.uk/Default.aspx?Main=ProductDetail.aspx&cat=cycle&w=0&ProdID=5360022185
http://www.wiggle.co.uk/Default.aspx?Main=ProductDetail.aspx&cat=cycle&w=0&ProdID=5360022186

tom

--
Don't believe his lies.

Tom Anderson said:

In fact, the City Jet's tread looks ideal for roads - lots of lovely
flat
bits of rubber to grab the tarmac.

But compound, stickiness of the material, varies even with totally slick
tyres. The harder the compound, the longer it lasts, at the expense of
grip.

........

Quoted message said:

Ah, i see. I suppose the kevlar stuff is effective against thorns and
whatnot, and so useful for offroad use, but can't handle the
technological
forms of sharp thing we have in cities - is that it?

No, thorns will go through as well, just like a nail would go through a
"stab-proof" vest if it was too thin and didn't have enough interwoven
layers. Maybe the occasional bit of lucky glass wouldn't penetrate but
basically it is a marketing gimmick or failed invention.

Quoted message said:

Quoted message said:

City Jet and Nimbus EX have a fair depth of rubber for natural
puncture
resistance,

Plus the Speccies have FlakJacket, which as far as i can tell means it
actually has a carcass, like any other tyre. Good work getting some
marketing mileage out of that, Specialized!

To be fair, it'll be a tougher casing with extra/different layers, maybe
better than the normal simple bit of Kevlar. I've not tried Amadillos but
maybe they really do provide more useful protection.

Quoted message said:

Quoted message said:

but skinny sidewalls to save adding further weight and stiffness.
Armadillo must be heavier/slower.

How big a difference is it really? The EX only weighs 550ish grams to
start with, so using a pair of armadillos isn't going to add more
than a
couple of hundred grams, surely? There may be bleeding-edge racers
for who
that matters, but for me, it's the difference between a glass of water
before i ride home or after!

100g+ is a lot for a tyre, but if you're not bothered about that or a
small increase in rolling resistance (or any extra money) then go for it.
(As far as I understand, tyres with stiffer sidewalls don't flex as well,
therefore don't roll as well).

Quoted message said:

While we're here, is Nimbus different to Nimbus EX? As in:

http://www.wiggle.co.uk/Default.aspx?Main=ProductDetail.aspx&cat=cycle&w=0
&ProdID=5360022185

Quoted message said:

http://www.wiggle.co.uk/Default.aspx?Main=ProductDetail.aspx&cat=cycle&w=0
&ProdID=5360022186

I can't remember what the difference is supposed to be. Previous versions
looked different anyway. EX is the only one of the two I have experience
myself with -- I suspect it is same/similar to new one except for tread
pattern.

~PB

Pete Biggs said:

Quoted message said:

Quoted message said:

City Jet and Nimbus EX have a fair depth of rubber for natural
puncture resistance,

Plus the Speccies have FlakJacket, which as far as i can tell means it
actually has a carcass, like any other tyre. Good work getting some
marketing mileage out of that, Specialized!

To be fair, it'll be a tougher casing with extra/different layers, maybe
better than the normal simple bit of Kevlar. I've not tried Amadillos
but maybe they really do provide more useful protection.

Sorry, didn't make myself clear - the FlakJacket is what the plain EX has;
the Armadillo has kevlar as well as that. FlakJacket is described as
several layers of woven aramid or something - basically, a very thick,
tough carcass.

Quoted message said:

Quoted message said:

Quoted message said:

but skinny sidewalls to save adding further weight and stiffness.
Armadillo must be heavier/slower.

How big a difference is it really? The EX only weighs 550ish grams to
start with, so using a pair of armadillos isn't going to add more than
a couple of hundred grams, surely? There may be bleeding-edge racers
for who that matters, but for me, it's the difference between a glass
of water before i ride home or after!

100g+ is a lot for a tyre, but if you're not bothered about that or a
small increase in rolling resistance (or any extra money) then go for
it. (As far as I understand, tyres with stiffer sidewalls don't flex as
well, therefore don't roll as well).

Actually, having read what you and others have to say, i'm leaning towards
an unarmoured tyre; it may not be much heavier or much more expensive, but
if there's no benefit, why bother at all? Now it's just between the City
Jet and the Nimbus ...

tom

--
This should be on ox.boring, shouldn't it?

In article <[email hidden]>, Pete Biggs <p@biggspomegrana
teremovehighlyimpracticalfruit.tc> writes

Quoted message said:

Tom Anderson said:

Ah, i see. I suppose the kevlar stuff is effective against thorns and
whatnot, and so useful for offroad use, but can't handle the
technological
forms of sharp thing we have in cities - is that it?

No, thorns will go through as well, just like a nail would go through a
"stab-proof" vest if it was too thin and didn't have enough interwoven
layers. Maybe the occasional bit of lucky glass wouldn't penetrate but
basically it is a marketing gimmick or failed invention.

In my experience the flak jacket tyres are very effective!

I commute daily in London. On normal hybrid tyres (nice thick rubber) I
used to get a puncture about once a month or so, typically a small piece
of glass working its way through the carcass

For the last 5 years I've used flak jacket tyres, on two different
bikes, and *never* had a puncture! That's in over 10,000 miles

I still pick up lots of pieces of glass, but they seem to get pushed out
of the tyre, not into it

Now that's only a sample of one person, but I'm impressed!

Sods law says I'll now get a puncture on the way home tonight...

Cheers
--
Ben Mack
Watchfront Electronics - Bespoke R&D - http://www.watchfront.co.uk/
Watchfront Internet - ADSL, Colo - http://www.watchfront.net/
Are you bricking it? - Firewalls - http://www.firebrick.co.uk/

Ben Mack said:

In article <[email hidden]>, Pete Biggs <p@biggspomegrana
teremovehighlyimpracticalfruit.tc> writes

Quoted message said:

Tom Anderson said:

Ah, i see. I suppose the kevlar stuff is effective against thorns and
whatnot, and so useful for offroad use, but can't handle the
technological
forms of sharp thing we have in cities - is that it?

No, thorns will go through as well, just like a nail would go through a
"stab-proof" vest if it was too thin and didn't have enough interwoven
layers. Maybe the occasional bit of lucky glass wouldn't penetrate but
basically it is a marketing gimmick or failed invention.

In my experience the flak jacket tyres are very effective!

Hang on, by 'flak jacket', do you mean 'a kevlar belt or similar', or do
you mean the Specialized FlakJacket tyres, which are just a thicker weave,
and *do not* have kevlar?

Quoted message said:

I commute daily in London. On normal hybrid tyres (nice thick rubber) I
used to get a puncture about once a month or so, typically a small piece
of glass working its way through the carcass

For the last 5 years I've used flak jacket tyres, on two different
bikes, and *never* had a puncture! That's in over 10,000 miles

Aha. Exactly what tyres? Make, model and serial number!

tom

--
.... the full attack expands into an unusual pseudosteganographic
strikeback methodology against peer to peer networks. -- Dan Kaminsky

Ben Mack said:

For the last 5 years I've used flak jacket tyres, on two different
bikes, and *never* had a puncture! That's in over 10,000 miles

I've had lots of punctures from small pieces of glass with various tyres
that were supposed to be "puncture resistant", but fewer with some tyres
that had no Kevlar or anything like that. The most successful tyres (in
terms of puncture resistance) have thicker tread, simple as that.

Anyway, a lot is down to where you ride exactly, how much of it is wet,
and how much of a lucky basket you are ;-)

~PB

"Tom Anderson" <[email hidden]> wrote

Quoted message said:

Hi again,

26-inch rims - are they basically all the same width? If so, does that
mean i can buy a tyre of any width to go on them? If not, how do i know
what widths i can buy? I've always assumed rims were a standard size, but
i've never actually had to buy new tyres before, so i've never thought
about it too hard.

The fundamental rule is that the width of tyre should be greater than the
inner surfaces of the rim. If tyres are wider than the braking surfaces
then the condition is guaranteed to be satisfied.

The fashion for road bikes in the 80's seemed to be to call tyres "25mm"
which were actually 18 or 19mm; I have rescued a couple of bikes from the
tip where the braking surfaces were wider.

"Tom Anderson" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Hi again,

26-inch rims - are they basically all the same width? If so, does that
mean i can buy a tyre of any width to go on them? If not, how do i know
what widths i can buy? I've always assumed rims were a standard size, but
i've never actually had to buy new tyres before, so i've never thought
about it too hard.

Wait! Why don't i read Sheldon Brown's highly informative article [1] on
the subject? Aha - so there *are* different sizes of rim, and it does
matter.

So, what width do i have? The current gignormous knobblocalyptic tyres say
26 x 2.00, but i assume the 2.00 refers to the tyre, since the rims aren't
two inches wide. There's nothing written on the rim itself - it's just got
bloody Decathlon branding. Well, except 'Rigida' in tiny letters - a make,
but no model. A bit of googling suggests that it might be a Sphinx:

http://www.rigida.com/eng/produits/mtb_double/sphinx_r.html

It's not a Taurus, since i don't have disc brakes. If it is a Sphinx, it
has an interior width of 16.8 mm, which according to Brown and Boeger's
table should accomodate a tyre 25-37 mm across; Rigida themselves say
25-48 mm. The tyres actually fitted claim to be 51 mm, which is a bit odd.

Am i on the right track here? Should i give up on buying new tyres and
just slickify my knobblies with some putty?

tom

[1] http://www.sheldonbrown.com/tire_sizing.html

As others have said: Slicks / skinny XC 1.5"s = OK.

Stick some tyres 2 and a half inches wide, and you might have problems. I
know my bikes rims have stickers saying something along the lines of that.

In article <[email hidden]>, Tom
Anderson <[email hidden]> writes

Quoted message said:

Aha. Exactly what tyres? Make, model and serial number!

You've got me there ;-)

--
Ben Mack
Watchfront Electronics - Bespoke R&D - http://www.watchfront.co.uk/
Watchfront Internet - ADSL, Colo - http://www.watchfront.net/
Are you bricking it? - Firewalls - http://www.firebrick.co.uk/