Keith A
03-08-2007, 04:03 PM
I just read some of the comments from Kirk Pacenti on CyclingNews and thought I'd pass them along here since there was some discussion recently about his bike that was on display at the NAHMBS....
Yet another mountain bike wheel size format, though, was introduced at the show this year by Kirk Pacenti (former Bontrager builder and now of Bikelugs.com). Pacenti was an early proponent of the 29" wheel movement, and still believes in the bigger wheel concept. However, as a frame designer, "tossing out fundamental frame design principles to accommodate the 29" wheel just doesn't sit well with me."
The alternate size he proposed is roughly 27.5" in diameter and essentially splits the difference between the current rivals. To be fair, the 'new' size isn't new at all, but rather uses the old 650B standard that's been around for ages. According to Pacenti, 650B can offer most of the 29" wheel's ability to roll over obstacles, but can retain most of the perceived acceleration advantage of 26" wheels, all while accommodating a broader range of rider sizes.
"It's just like a pendulum; you get this idea and it grows and takes off, and it goes to an extreme. Fifteen years ago, the view was that, if 16" chain stays were good, 15" ones were better and everyone was going with an elevated stay [in order to reduce the chain stay length]. Here we are, fifteen years later, and we're all back running 16.75" stays. So I kind of view it that way. In general, I think it's the best of both worlds."
Tires on Pacenti's show bike were hand-trimmed and stitched from WTB 29" tires, but Panaracer has apparently signed on to produce proper 650B mountain bike tires. Pacenti says that he's already sold about 500 hundred tires to both Rivendell (who has been advocating the 650B for some time now) and "another company". The idea certainly holds some merit, and we'll be eagerly waiting to see where this one goes (and no, we're not adding 650B wheels to our ongoing 26" vs. 29" experiment, so don't even ask!).
Yet another mountain bike wheel size format, though, was introduced at the show this year by Kirk Pacenti (former Bontrager builder and now of Bikelugs.com). Pacenti was an early proponent of the 29" wheel movement, and still believes in the bigger wheel concept. However, as a frame designer, "tossing out fundamental frame design principles to accommodate the 29" wheel just doesn't sit well with me."
The alternate size he proposed is roughly 27.5" in diameter and essentially splits the difference between the current rivals. To be fair, the 'new' size isn't new at all, but rather uses the old 650B standard that's been around for ages. According to Pacenti, 650B can offer most of the 29" wheel's ability to roll over obstacles, but can retain most of the perceived acceleration advantage of 26" wheels, all while accommodating a broader range of rider sizes.
"It's just like a pendulum; you get this idea and it grows and takes off, and it goes to an extreme. Fifteen years ago, the view was that, if 16" chain stays were good, 15" ones were better and everyone was going with an elevated stay [in order to reduce the chain stay length]. Here we are, fifteen years later, and we're all back running 16.75" stays. So I kind of view it that way. In general, I think it's the best of both worlds."
Tires on Pacenti's show bike were hand-trimmed and stitched from WTB 29" tires, but Panaracer has apparently signed on to produce proper 650B mountain bike tires. Pacenti says that he's already sold about 500 hundred tires to both Rivendell (who has been advocating the 650B for some time now) and "another company". The idea certainly holds some merit, and we'll be eagerly waiting to see where this one goes (and no, we're not adding 650B wheels to our ongoing 26" vs. 29" experiment, so don't even ask!).