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