This is a poorly-focused picture of a very cool bike, one that I’ve been anxious to see and ride: a Jamis Dragon 650B.
650B is a wheel/tire specification. In short words, 650B is halfway between a 26″ and a 29″ wheel. 650B proponents say that this size gives the rider the benefits of a 29er (low rolling resistance, better traction, smooth ride) without the limitations (geometry issues, toe overlap, high center of gravity). I can’t say if 650B will stick around for the long haul or not, but it is gaining momentum. More and more tires, wheels and forks are available all the time. Things look pretty good, but selection is not what it is in the 26 and 29 worlds.
This particular 650B is composed of several interesting pieces: Steel Reynolds 853 frame. A very nice White Brothers Loop TCR fork. American Classic wheels. Syncros (a division of Ritchey) cockpit and seat post. And a Shimano SLX drivetrain.
Know what? I did that, too. I said to myself, “That’s one helluva bike, marred by an SLX drivetrain.” It’s not that I thought SLX was bad, I just thought it was pretty darn average. However, we’ve built four Dyna-Sys (10-speed) SLX bikes this week and they all shift really good, so I’m rethinking my stance.
A few words about Dyna-Sys. When Shimano introduced their 10-speed mountain bike drivetrains, it looked very much like a quick response to SRAMs very awesome XX technology. A closer look indicates that Shimano spent a long time working on the entire system. Interesting bits include closer-ratio rings in the front, a Dyna-Sys specific chain and two big changes to the cassette: a huge 36-tooth cog and a tightening of the middle ratios. The idea is two-fold: make front shifting better and make the Primary Driving Gear (Shimano speak for the middle ring) more usable via the wider range of ratios in the back.
Most of us are used to Rock Shox or Fox or maybe even Manitou forks, so this White Brothers Loop thing might seem a bit odd. It is for real? Yes, it is. One of the challenges high-end fork manufacturers face is the threshold between locked-out and active. For instance, you don’t want the fork to bob when you’re pedaling, but you’d like it to absorb the hit if you run over a log. Everybody uses some sort of internal valving techniques to achieve this platform, and the Loop uses magnets in its Aura damper. Very clever. The TCR in the fork name refers to its possible adjustments: Threshold, Compression damping and Rebound damping. All in all, it’s quite a fork.
The whole package is great. Beauty is in the eye of the beholder, but I think the frame is gorgeous. The green is sparkly in the light and small-diameter steel tubes appeal to me. The American Classic rear hub makes that neat patter sound that American Classic freehub bodies make. Plus the ride is something — but something that’s difficult to quantify. It’s not as whippy as a racy 26″ bike. It’s also bigger, more substantial, but without that too-big feeling some 29ers engender. In short, it’s different, but different in a good way, like your favorite dish made with a new ingredient, like a Hendricks martini.