Weird Tire Size / Rim Size

[noulis4]

Hello.

From time to time when i had some work on my bike involving tires/tubes/etc, i have
wondered about the size of my tire. I had done a search a long time ago and found
many articles including http://sheldonbrown.com/tire-sizing.html which explains much
and also has a sizing chart. I also read some very good threads here.

I have a 26" MTB (in Greece/Europe if it matters). My rim says 559-19.
From what i read 559 is the common diameter for 26" MTB and 19mm is the rim
width. According to the above sizing chart the recommended tire size is 28-44mm.
Other articles i found through google mention similar range. However, my tires say
53-559 (26" x 1.95). Now, here are two thought i had.

1) 1.95" * 25.4=49.53mm.Shouldn't it be the same as the metric value which is 53 ?
2) 53mm is quite larger than 44mm which is the largest recommended value.

The above two thoughts, combined with the fact that these tires are the original ones
that came with the bike (certainly the manufacturer knows more than me) give me
the impression that i haven't understood the articles well and my thoughts are flawed.

What do you think ? Is so large tire good for my rim ?
Thank you for your time.

[Bill]

Pretty good question to asked. To be honest with you most I can say is someone here brought up a similar question and one stated that the tire sizing is not always exact. Each tire company stood with the relative sizes but somehow the true size of it was not exact. Through the years things changed like one company would say 26" x 1.95" to where it really was 1.75" or something like that. Wish I knew the exact thread it was ahh here is one .... http://forums.bikeride.com/thread-1299.html . Sorry not much of an expert on this question.

[noulis4]

(08-08-2010, 07:50 AM)Bill Wrote:  Pretty good question to asked. To be honest with you most I can say is someone here brought up a similar question and one stated that the tire sizing is not always exact.

Yeah, i think you're right. I read what my brother's tires say and the front says
26" x 2.00 (52 x 559) and the rear says 26 x 2.00 (47 x 559). (It seemed weird
to me that it has different size front and back). So, i gather that the ISO size is the
correct value and the inch counterpart is bogus/approximate.

I will google a bit more about the larger width (53 >> 44).

Thank you for replying.