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Dirt Rag Articles
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Tester: Andy Bruno
Age: 39
Height: 6'0"
Weight: 180lbs.
Inseam: 33"
Vital Stats
Country of Origin: USA
Price: $5,500 complete bike as tested, $2,900 Ti frame; Neo Moto Tires $55
Weight: 26.08lbs.
Sizes Available: Custom
Contact: www.bikelugs.com
If you've been asking yourself, "How can I rationalize buying yet another bike?", along comes Kirk Pacenti with your answer—650B. That's right, the semi-obscure wheel size used mostly on touring and road bikes is being adapted to mountain bikes. And Dirt Rag got a prototype bike and tires from a guy who wants to bring 650B's to the mountain bike masses.
Just to be clear, this review is more about wheel size than it is about the actual bike we got from Pacenti. He's a custom bike builder and he plans on building 650B customs in both steel and Ti, but his main focus now is tires. If you read "The Big Wheel Mountain Bike Story" in Dirt Rag Issue #130, the genesis of 650B mountain bike wheels will sound familiar with a slightly different twist. While the absence of a mountain bike-specific 29" tire slowed the development of 29ers, Pacenti was able to score a deal with Panaracer and is currently working with them on a series of 650B Pacenti branded tires. This he hopes will be the incentive other builders need to start producing 650B specific mountain bikes.
Size Matters
As far as size goes, 650B's (or 27.5ers) fit squarely between the standard 26" and 29" mountain bike wheel sizes. There are currently several 650B bikes, wheels, and tires on the market today due in a large part to the popularity of the wheel size in Europe. One of the more recent and notable 650B bikes in the U.S. is the Rivendell Bleriot, an all-around road, trail, and touring bike mentioned in DR #126. But up until now there hasn't been a dedicated 650B mountain bike.
With the market chock full of well-made, high performance 26" and 29" mountain bikes, why would we need a 650B? According to Kirk Pacenti, the answer is frame geometry. In designing the 650B, Pacenti wanted to incorporate the performance advantages of the bigger 29" wheels but also experienced their inherent limitations when it comes to frame design and geometry. These limitations translate into compromises in frame building like undesirable chainstay length and/or bottom bracket height. Apparently it's not as much of an issue for 29" hardtails, but he says, "With 4" of travel or more on a 29"-wheeled bike you pretty much have to chuck fundamental frame design principles out the window!"
His idea is that you get the best of both worlds with 650B—they're not too big, they're not too small. The "right size" allows builders to utilize proven 26"-wheeled geometry while taking advantage of the bicycle handling benefits of bigger wheels. "Frame designers 'get it' right away when I talk to them about 650B wheels. I almost never have to explain the advantages of the size as it pertains to frame geometry..." says Pacenti. He stressed his belief that there are appropriate applications for 24", 26", and 29" wheels, but he believes the 650B size offers a greater range of versatility than the other sizes. And judging from press releases that come across my desk and gossip around the industry, a number of other builders agree with him and have 650B mountain bike projects in the works.
Prototype
The prototype 650B bike we got from Pacenti is a clean-looking hardtail 3/2.5 titanium frame painted in a pearlescent white. Up front there's a modified White Brothers Magic 100 fork cut down from their 29er version and optimized for 650B wheels. Pacenti used the White Brothers fork because its modular design lends itself to custom configurations, but he said that any off-the-shelf 29er fork and even some 26" forks could be used.
The linchpin(s) holding this project together are the tires, and there are currently three Pacenti branded 650B Panaracers in the works: the Neo-Moto, a full-on 2.3" knobby; the Mini-Moto 650B x 40mm randonneuring/touring mini-knobby tire; and the Quasi-Moto, a 650B x 52mm semi-knob, hard pack/marathon tire. Our test bike came with the Neo-Moto, borrowing aspects from both the Panaracer Rampage and the Kenda Nevegal. The tires were mounted on custom Velocity Synergy 650B rims built up as a Cane Creek Zonos Disc Team wheelset. Other interesting bits and pieces include Shimano Deore XT crank/bottom bracket, front and rear derailleur, SRAM Rocket Twist Shifters, and Avid Juicy Seven disc brakes.
Riding the 650B
What's it like riding on 650Bs? In the spirit of full disclosure, I've got to say that the vast majority of my mountain biking has been on 26" wheels. I don't own a 29er but I have ridden a few. And I have to admit, I love big wheels. So were the 650B's big enough? I felt like I was getting the benefit of bigger wheels—faster and smoother rolling over rocks, logs and roots. Riding 29ers in the past in very tight sections of the trail sometimes I've felt like the wheels were almost too big and the bike wasn't as nimble as I'd like. On the Pacenti I didn't notice this as the bike felt right at home on tight, twisty singletrack, swoopy trails through the woods, or bombing downhill. The geometry of the bike is slightly different from other bikes I've ridden with twin 72° head and seat tube angles. The Neo-Moto's tread design along with the longer contact patch of the 650B wheel provided great traction climbing and in all kinds of trail conditions. The tires handled particularly well in the corners because of the large, beefy side knobs.
What didn't I like about the bike? Not much, really. If the bike were custom built for me I'd probably choose a few different components. The White Brothers fork was alright by me, but others around the office seemed to think it didn't perform as well as expected. Kirk Pacenti also told me that the chainstays on the bike are a bit longer than they need to be, but since it was a prototype they wanted to make sure the tires would fit. I'm not sure if I would notice the less than 1/2 inch difference, but it's worth mentioning.
The bottom line is that I'm curious to see what else is possible with 650B's. As far as hardtails go, the prototype I rode was a fun all-around bike. But if the real benefit of 650B's is on bikes with greater than 4 inches of rear travel, you've got my attention. I'd like to see more.
| Exclusive Dirt Rag Web-Only Extras For Pacenti 650B | Make: Pacenti
Model: 650B
Model year: 2007
Type: 650B Mountain
Country of origin: USA
Wheel size: 650B
Frame material: 3-2.5 Titanium
Fork: White Bros. Magic 100
Handlebar: Ritchey WCS Rizer
Stem: Ritchey WCS
Headset: Cane Creek
Bottom bracket: Shimano Deore XT
Crank: Shimano Deore XT
Chain: SRAM
Saddle: fi'zi:k Nisene HP Wing Flex
Seatpost : Ritchey WCS
Front hub: Cane Creek Crono 3.0 Mountain 28 spokes
Rear hub: Cane Creek Crono 3.0 Mountain 28 spokes
Front derailleur: Shimano Deore XT
Rear derailleur: Shimano Deore XT
Shifters: SRAM Rocket Twist Shifters
Cassette: 8 speed
Brakes: Avid Juicy 7
Rims: Velocity Synergy 650B
Tires: Panaracer/Pacenti Neo-Moto 650Bx2.3 Tubed
Sizes: custom
Colors: White Pearl |
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| Comment from DwayneBrooks on 2008-07-01 |
| cool links, thanks!, |
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| Comment from Kraunchfr on 2008-04-03 |
| You see things and you say, Why? But I see things that never were and I say, Why not? |
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