News & Updates
01.21.2010 - Mounatin Bike Action - Online
|Getting behind 650B
you noted recently, 29ers roll over chatter and trail obstacles better
than 26ers but the wheels are heavy. A well-executed full-suspension
650B bike would enjoy most of the 29er's superior roll and the wheels
and tires would be only marginally heavier than comparable 26" wheels.
In the June 2009 issue of MBA, Chris Cocalis is quoted as saying,
"This mid-size wheel has all of the performance advantages of the
29-inch wheel, but without all of the negative rotating weight and
chassis fit issues." My rims of choice, Stan's ZTR 355, are already
available in 650B, as are my trailbike tires of choice, Kenda Nevegals
(in both 2.1 and 2.35 widths). And trailbike builders are eager to
build a 650B full-suspension trailbike. I emailed Pivot, and they
replied that they would love (their word, not mine) to build such a
bike and would do so just as soon as one of the three big fork makers
committed to producing a suitable fork.
I believe that your editorials in the print magazine carry real
weight in the industry. I also believe that many, many trail riders
would buy such a bike, justifying the development and production costs
of the fork maker. I was wondering if you would be willing to make the
case in print.
I have and will conctinue to make the point that the origin of both 26
and 29 inch wheels was a matter of convienience--not science. 2 x
1.75-inch whees were the only alternative that wold work with the
components available when mountain bikes were "invented." Hub withs,
bottom bracket and crank designs would nbot support 700C or even a
650B format. Wider hubs and dirt-specific drivetrains now make larger
whels possible, but we chose a conventional 700C road bike wheel to
base 29ers from--again, because it existed. Are 29ers best? is the
26-inch format valid? Is 650B (another off-the-shelf wheel) best? Now
that off-road cycling is established, we owe it to ourselves to
evaluate the best wheel-diameter compromise that will fit into all
modes of the sport--XC racing to long-travel gravity stuff. Science,
not religious fervor should make the call this time.
The limitations of 29 inch wheels are especially troublesome when
suspension travel exceeds 5 inches. At this point, the mid-sized 650B
allows more tire clearance, bigger tires and lighter wheels--all of
which play well to the needs of the medium-travel trailbike as well as
the downhill bike set.
That said, Trek and Specalized are at war with each other at
present to establish themselves as the inventors and leaders of the
29-inch movement. With the full force of the two big-brand's marketing
departments (and also their buying power) focused on 29ers, there is
little hope of any other wheel format taking hold until the limitations
of 29ers have run their course. Once that has happened, Trek and
Specialized's design groups will no-doubt fly the alternative-wheel
diameter flag as their own.