Well, 650B is 584mm, 700C 622mm, 26" MTB 559mm. Not huge differences I guess, but for my World Voyageur it made enough difference in standover height to make a 23" frame near ideal rather than too large.
As to the claimed advantages of smaller wheels, the Rivendell Reader or their website can probably expound on that better than I can. It's probably the same debate as applied to the Moulton small wheel machines a couple of decades earlier, except the difference in wheel size versus 700C is much smaller. The 650B was of course first used on old French touring bikes, but how that exact size became established, I don't know. The touring bikes of course used fatter tires than the tubulars on racing bikes, so maybe the two at one time would up having similar tire OD's.
I think Rivendell is mostly responsible for the comeback of 650B on their Saluki and now other models. I suppose Grant could have chosen 26" MTB size wheels, and in fact many thought he was crazy for trying to resurrect 650B. But it seems to have worked out, though parly because Grant got Panaracer to make some relatively light, relative fast new 650B tires to his design. Now others including Grand Bois are offering 650B tires and some new 650B rims have beeen introduced as well.
I will say that lots of people, including me, just like the way 650B wheels feel, especially with the modern rims and tires. Now if Grant had gotten Panaracer to make a lightweight tire with a road tread in 26" MTB size, and someone had introduced a rim optimized for them, maybe those would have felt just as good. But those of us who had old French bikes with 650B (in my case an old LeJeuene tandem)are happy he did it the way he did.
Regards,
Jerry Moos
Big Spring, Texas, USA
> From: Jon Spangler <hudsonspangler@earthlink.net>
\r?\n> Subject: [CR]Why 650B?
\r?\n> To: classicrendezvous@bikelist.org
\r?\n> Cc: "Jerry Moos" <jerrymoos@sbcglobal.net>
\r?\n> Date: Wednesday, January 7, 2009, 12:22 PM
\r?\n> Jerry and all,
\r?\n>
\r?\n> Your post brings to mind an issue I've never been able
\r?\n> to understand
\r?\n> very well: why are there so many wheel diameters and and
\r?\n> tire sizes
\r?\n> within such a small range? It's almost overwhelming.
\r?\n>
\r?\n> What makes a 650B wheel superior to a 700C or a 26"
\r?\n> MTB wheel? Why
\r?\n> would one want a 650B bike instead of a 26" wheeled
\r?\n> one? The
\r?\n> differences in rim diameter seem so small as to be
\r?\n> insignificant, but
\r?\n> I know lots of 650B fans here on CR and elsewhere.
\r?\n>
\r?\n> Thanks in advance for this discussion.
\r?\n>
\r?\n> Jon Spangler
\r?\n> (who is off to Mac World Expo in San Francisco after this
\r?\n> post to get
\r?\n> help with our "vintage" Apple G4 desktop
\r?\n> computers from 2001-2003.
\r?\n> They might as well be 1912 Pierce Racers... :-)
\r?\n>
\r?\n> Alameda, CA USA
\r?\n>
\r?\n>
\r?\n> On Jan 7, 2009, at 6:17 AM,
\r?\n> <classicrendezvous-request@bikelist.org>
\r?\n> <classicrendezvous-request@bikelist.org> wrote:
\r?\n>
\r?\n> >
\r?\n> > Date: Tue, 6 Jan 2009 21:01:52 -0800
\r?\n> > From: Jerome & Elizabeth Moos
\r?\n> <jerrymoos@sbcglobal.net>
\r?\n> > To: <ooki1998@yahoo.com>,
\r?\n> > Classic Rendezvous
\r?\n> <classicrendezvous@bikelist.org>,
\r?\n> > Tom Harriman <transition202@hotmail.com>
\r?\n> > Subject: RE: [CR]wtb- touring bikes and small bikes
\r?\n> > Message-ID:
\r?\n> <376590.58913.qm@web82208.mail.mud.yahoo.com>
\r?\n> > In-Reply-To:
\r?\n> <BAY140-W36B8B1FED16238504D9814F0DF0@phx.gbl>
\r?\n> > Content-Type: text/plain; charset="us-ascii"
\r?\n> > MIME-Version: 1.0
\r?\n> > Precedence: list
\r?\n> > Reply-To: jerrymoos@sbcglobal.net
\r?\n> > Message: 7
\r?\n> >
\r?\n> > Don't know about the Trek, but another nice thing
\r?\n> about the World
\r?\n> > Voyageur is it has a high BB that lends itself nicely
\r?\n> to a 650B
\r?\n> > conversion. I converted my World Voyageur to 650B
\r?\n> because it was
\r?\n> > just a little too tall with 27" wheels, but the
\r?\n> result was so nice
\r?\n> > that I picked up another World Voyageur that would fit
\r?\n> me with 27"
\r?\n> > wheels, but I may convert to 650B anyway.
\r?\n> >
\r?\n> > Regards,
\r?\n> >
\r?\n> > Jerry Moos
\r?\n> >
\r?\n>
\r?\n> Jon Spangler
\r?\n> Writer/Editor
\r?\n> Linda Hudson Writing
\r?\n> 510-864-0370/FAX 864-2144
\r?\n> MOBILE 510-846-5356
\r?\n> hudsonspangler@earthlink.net