07.27.2007 - Bike Radar
Pacenti introducing 650B MTB tires
By Gary Boulanger
Mountain bike wheel and tire standards have centered around
the 26-inch (559mm rim diameter) platform, until Wes Willits and Gary
Fisher brought 29-inch (622mm) to market nearly 10 years ago. Better
rolling, they said, and by the looks of the current 29er movement,
they're onto something. Kirk Pacenti believes in another size, known as
650B (584mm), for many legitimate reasons. Heaven help us!
According to Pacenti, the 650B size for off-road use has plenty to get excited about:
* With 650B wheels (which measure 27.5" in diameter, half-way
between 26- and 29-inch wheels), full-suspension bikes can be produced
with four to six inches of travel and throughout a wide range of frame
sizes without abandoning proven 26-inch wheel frame geometry.
* 650B wheel bikes can be designed for a wide variety of uses from XC racing to 4X and DH racing.
* 650B wheel bikes can accommodate riders 5' 3" to 6' 4" tall or more.
* 650B wheels offer great obstacle roll-over capabilities for a smoother ride.
* Consumers are already demanding 650B bikes and bike designers are producing the bikes.
"What I believe 650B wheeled mountain bikes will allow builders to
do, is to utilize proven 26-inch wheeled geometries, coupled with the
largest wheel possible in a bike with little or no geometry
compromises," Pacenti said. "As 140mm travel bikes become the norm
(even for XC bikes) the 650B wheel size is going to make even more
Hard to argue with Pacenti, but what about the effort it'll take to
get the big tire makers on board? Pacenti has already covered that
rocky ground. A Pacenti-designed and branded Panaracer-made 650B tire -
the Neo-Moto - is currently in production and will be
available by mid-September for $54.95US each. Current handmade samples
weigh approximately 740g, according to Pacenti. In addition, White
Brothers is producing suspension forks for the new wheel size, and
Velocity USA, which has built 650B rims for the bicycle touring market
for years, is already in production of their new Blunt, all-mountain MTB rim.
Because the 650B wheel size is compatible with many 26-inch wheel
components numerous parts are already available. For instance, Maverick
forks can be easily optimized for 650B wheels with a travel reduction
kit, and some current 26-inch and all current 29-inch disk specific
suspension forks will work with the 650B wheel size.
"The 650B wheel size makes more sense for a company looking to produce big wheeled bikes in the 100 - 150mm travel category"
"Kirk's forward thinking vision is correct in that 29'er wheels
don't work well for frames with more than 100mm of rear travel," adds
Noel Buckley of Knolly Bikes.
"While working on the design of a 29er version of our new Endorphin
frame, we started realizing that serious compromises would need to be
made to the frame geometry due to undesirable forward wheel paths,
chain stay lengths, and BB height all caused by the large 29" wheel
"Kirk knows what he's talking about," Buckley added. "The 650B wheel
size makes more sense for a company looking to produce big wheeled
bikes in the 100 - 150mm travel category because they get the rolling
benefits of the larger tire, but don't have to modify frame geometries
much, or have to contend with the design compromises imposed by 29 inch
As many as a dozen manufacturers will have 650B parts and components
ready for this year's Interbike trade show and distribution of the new
Pacenti 650B tires will be handled by a number of well-known
distributors. (A list of distributors will be available soon.)
"I am fully committed to the 650B wheel mountain bike," says
Pacenti. "I have been receiving daily inquiries from custom builders
and even consumers who are very interested in the wheel size. Support
for this project has been overwhelming. I truly believe 650B wheel
bikes have a bright future in mountain biking."
Pacenti's 650B for-the-dirt evangelism is catching on. Numerous
independent bike designers are fully embracing the new 650B wheel size
and producing 650B frames. There are even some bigger players testing
out the concept. The current list includes:
* Ahrens Cycles
* Carver Bikes
* El Camino Fabrication
* Engin Cycles
* Independent Fabrication
* Kent Eriksen
* Origin 8
* Pacenti Cycles
* Rawland Cycles
* Rock Lobster Cycles
* Siren Cycles
* Tomac Mountain Bikes
* Turner Suspension Bikes
* Vicious Cycles
* Walt Works
* Willits Brand
* ZR Cycles