[CR] "650 wheels"

(Example: Framebuilders:Alberto Masi)

In-Reply-To: <001301c05cdb$4195bf60$d9451b3f@5dstx>
References: <001301c05cdb$4195bf60$d9451b3f@5dstx>
Date: Sun, 3 Dec 2000 11:16:11 -0500
To: "Phil" <pdscott@gte.net>, <classicrendezvous@bikelist.org>
From: "Sheldon Brown" <CaptBike@sheldonbrown.com>
Subject: [CR] "650 wheels"

"Phil" wrote:
>I have a french touring frame, Simplex dropouts, that has a extra
>set of braze on bosses , one above the water bottle mounts on seat
>tube and another on bottom of top tube, It has cantilever brake
>mounts for 650 wheels. no decals or holes for head tube badge.

The phrase "650 wheels" by itself is basically meaningless, and if you make a habit of talking in such shorthand, you're liable to get sold stuff that won't fit your bike.

There are 3 kinds of "650" rims/tires: 650A (590mm), 650B (584 mm) & 650C (571 mm.)

If you go into a typical bike shop and ask for "650" they'll most likely come up with the 571 size, because this is the only "650" size used on current production bikes available in the U.S. It's mainly used on triathlon bikes and the like. This size is totally useless for touring, because only ultra-skinny racing tires are made to fit.

The 590 mm/650A size is fairly common, because it is found on millions of old English 3-speeds that keep on rolling because they're nearly indestructible. The French designation "650A" is not commonly used in the U.S.; this size is more commonly known by its English marking: 26 x 1 3/8".

The 584 mm/650B size is the least common of the three, at least in the U.S. French touring bikes made for heavy-duty use used this size, and this is almost certainly what your frame was built for. Tires and rims are very hard to find in this size, but we stock them. See: http://sheldonbrown.com/harris/tires.html#584

I realize that this may seem pedantic to some readers, but if you talk to anybody who's been in the bike biz for a while, they'll know that hundreds of thousands, if not millions of person-hours have been wasted resolving confusion resulting from this sort of mix up, with people buying the wrong size tires and often destroying them trying to get them to fit on the wrong size rim.

I have a whole on-line article dealing with the arcana of bicycle tire sizing, and with the modern, universal ISO/E.T.R.T.O system that is gradually replacing the old national designations--see: http://sheldonbrown.com/tire-sizing.html.

Sheldon "ISO" Brown Newtonville, Massachusetts +------------------------------------------------------+ | One of my very favorite singer/songwriters is the | | French folkie Gabriel Yacoub | | His discs are hard to find, but worth looking for, | | both his solo work and his earlier recordings with | | the Breton group Malicorne. | | http://sheldonbrown.com/music.html | +------------------------------------------------------+
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