tire sizes
 

Turning the place into a DIY shop was the best
thing I ever did! Surprisingly, as it was never
"closed" and there were always tons of
goofballs working on their wierd projects.
But now, the enthusiasm and atmosphere is much
better! Or maybe I'm reading into this?

Well, now my next idea is to print small
posters which will illustrate key aspects.

Here is one image [1] I found on the net
explaining the tire size systems.

1) Anyone wants to add anything to it?

2) Of the systems I prefer the ISO (ETRTO),
I understand the old English inch system
looking on a tire, and the French system
I understand/"remember" looking on that
image... :)

But wasn't there yet another system that was
similar in style to the French system on the
image? Only this was super-confusing because
during the years the same designation
actually took on different meanings?

3) I'll put a small textbox onto that image
before I print it saying "beware of the
drive" (rotation inclination) and perhaps
"put the size label by the valve". Any other
time-tested wisdom? Just keep it short and
simple :)

[1] http://user.it.uu.se/~embe8573/bike/tire-size.png

--
underground experts united
http://user.it.uu.se/~embe8573

tire sizes
 

Today there was a bicycle trailer and
I examined the wheels. The tires were Nokia,
made in Finland, 24x2. But there was also
another marking:

2 - 19 3/4

Anyone knows what that means?

--
underground experts united
http://user.it.uu.se/~embe8573

tire sizes
 

Emanuel Berg wrote:

Today there was a bicycle trailer and
I examined the wheels. The tires were Nokia,
made in Finland, 24x2. But there was also
another marking:

2 - 19 3/4

Anyone knows what that means?

According to this site [1] (in Swedish)

2 - 19 3/4 (24x2)

is

50-507

OK, so 2" = 50.8mm ~= 50mm so that checks out.

If 19 3/4 is the inner diameter in inches then
that sort of checks out as that is equal to
501.65 mm. Perhaps that is an old tire size and
today 507 is the closest? Difference is
only ~5 mm.

[1] http://www.bytcykelslang.nu/dackstorlek/

--
underground experts united
http://user.it.uu.se/~embe8573

tire sizes
 

On 01/07/2018 01:21 AM, Emanuel Berg wrote:
Turning the place into a DIY shop was the best
thing I ever did! Surprisingly, as it was never
"closed" and there were always tons of
goofballs working on their wierd projects.
But now, the enthusiasm and atmosphere is much
better! Or maybe I'm reading into this?

Well, now my next idea is to print small
posters which will illustrate key aspects.

Threads. I *always* have to do a double check on which threads are
LH/RH wrt to pedals/bottom brackets. You probably have to run up you're
own poster, but text would be fine. It'd save a lot of jammed BBs imho.

tire sizes
 

On 1/7/2018 1:58 AM, Emanuel Berg wrote:
Emanuel Berg wrote:

Today there was a bicycle trailer and
I examined the wheels. The tires were Nokia,
made in Finland, 24x2. But there was also
another marking:

2 - 19 3/4

Anyone knows what that means?

According to this site [1] (in Swedish)

2 - 19 3/4 (24x2)

is

50-507

OK, so 2" = 50.8mm ~= 50mm so that checks out.

If 19 3/4 is the inner diameter in inches then
that sort of checks out as that is equal to
501.65 mm. Perhaps that is an old tire size and
today 507 is the closest? Difference is
only ~5 mm.

FWIW, I've found the hard way that just a few millimeters difference in
bead seat diameter means things won't work at all.

[1] http://www.bytcykelslang.nu/dackstorlek/


There are also these web pages:

http://www.sheldonbrown.com/tire-sizing.html
and
http://www.sheldonbrown.com/cribsheet-tires.html

I've found them to be handy.

--
- Frank Krygowski

tire sizes
 

Frank Krygowski wrote:

FWIW, I've found the hard way that just a few
millimeters difference in bead seat diameter
means things won't work at all.

OK, it'll be interesting to find out...

There are also these web pages:

http://www.sheldonbrown.com/tire-sizing.html
and
http://www.sheldonbrown.com/cribsheet-tires.html

I've found them to be handy.

Great, thanks.

--
underground experts united
http://user.it.uu.se/~embe8573

tire sizes
 

Tosspot wrote:

Turning the place into a DIY shop was the
best thing I ever did! Surprisingly, as it
was never "closed" and there were always
tons of goofballs working on their wierd
projects. But now, the enthusiasm and
atmosphere is much better! Or maybe I'm
reading into this? Well, now my next idea is
to print small posters which will illustrate
key aspects.

Threads. I *always* have to do a double check
on which threads are LH/RH wrt to
pedals/bottom brackets. You probably have to
run up you're own poster, but text would be
fine. It'd save a lot of jammed BBs imho.

Does that differ on road bikes?

Because what I remember it is always the same?
LH on the left side pedal, LH on the BB
nut/ring which is also on the left side, and
the right pedal RH as per usual?

Put the bike upside down, string/block the
crank, put the wrench vertically facing up,
pull against the front wheel with the wrench in
a pipe - same on both pedals?

Also one can think of the pedals, to
disassemble (remove), pull the way you don't
pedal when riding the bike.

I heard there is an English version of this
(which is supposedly French) and on the
English, everything is RH. As for me, so far
I have only seen the above (French) scenario...

--
underground experts united
http://user.it.uu.se/~embe8573

tire sizes
 

What does the letter "B" denote in the French
tire size system?

E.g., this tire

56-584 27.5x2.20 650-56B

?

--
underground experts united
http://user.it.uu.se/~embe8573

tire sizes
 

Today there was a bike with the following
configuration WRT tires:


ISO (ETRTO) England France
--------------------------------------------------
front 56-584 27.5 x 2.20 650-56B
rear 26 x 1.5 x 2
--------------------------------------------------
diff 1.5 .20
diff (mm) 38.1 5.08


This is pushing it, right?

Besides, even so, better the other way
around, right?

--
underground experts united
http://user.it.uu.se/~embe8573

tire sizes
 

On 1/9/2018 3:01 AM, Emanuel Berg wrote:
What does the letter "B" denote in the French
tire size system?

E.g., this tire

56-584 27.5x2.20 650-56B

?


B= Second revision.

'700' started out at 642mm (historically measured like wagon
wheels at the very outside diameter, 700mm). As roads
improved and tires narrowed, a new smaller lighter version
of 700 at 635mm appeared so the 642mm became "700A" and the
new one "700B".

(Since everyone just made things up to suit their
need/desire, there were two 700B, both at 1995mm=635mm and
1992mm=634mm)

Progress being inscrutable and subjective, a later revision
gave us 622mm, the still current 700C. There was a short
lived 587mm 700D, smaller yet, which failed the popularity
contest (pass/fail scoring) in the 1980s.

Lest you think that we moderns are more rational or smarter
than The Ancients, please note that your example of 650B was
known as a 26" size (26 x 1-3/4) for a hundred years and
nearly died out before being rebranded as 'twenty seven and
a half' because it's in the middle of the 26" tire range and
smaller than 27 inches.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971