August 11, 2007

Downhill bike finally *done*

So I’ve been through a few iterations, and some various forks (at last count, a WB135, A Lyrik w/eccentric hub, an old Hanebrink, and a modified Y2K Marzocchi Junior T) but I think the setup is now finalized. This sucker takes corners like it’s on rails and the combo of the big wheels (with beefy dual-casing Nevegal tires) and 6″/6.5″ of travel front and rear make it pretty much capable of running over anything you’re dumb enough to hit. I’ve named this model the El Guapo (“Jefe” was taken…)

I’m really happy with the new fork – Feldman got it off Craigslist in trade for some old crap brakes, and I sent it in to WB for a new left stanchion and some seals and bushings (as well as the fork guards). The fork (which is essentially the same as the current Groove 180 and Groove 200 forks, except for it’s 2001 era damping leg) is perfect for 29″ wheels, because it’s got plenty of clearance under the crown for the wheel (you do have to raise the lowers all the way up, though) and it’s got a sweet 120mm axle spacing setup – which lets you use a 120mm hub, or a DISHLESS 110mm one (which is what I’m doing, since I already had a 110 wheel). Very cool, especially for this application, since I want the strongest front wheel I can manage to build. Combined with the 150mm/12mm thru-axle rear, this is probably one of the burliest 29er wheelsets you can get. I could have gone with Kris Holm hubs over the Rhynolites, but I’m only 150 pounds, so I figured the Rhynos would be fine.

I had several concerns when designing this sucker, notably:
-Lateral stiffness. I can honestly say that this frame is the stiffest full suspension frame I’ve ridden. The combo of the massive front triangle tubes (45mm downtube, 38mm toptube, 32mm seat tube) and the 22mm axle pivot (using a sweet Primo bottom bracket from Dan’s Comp) mean that there’s practically no lateral flex or play. Honestly, I think it’s almost as stiff as a hardtail.
-Reasonable wheelbase and chainstay length. Given that I wanted to run a front derailleur, and I was limited to crappy E-type ones (the “e” is for “excrement”) the chainstays had to be a little longer than I could have otherwise made them (they’re 440ish mm, or about 17.3″). I will probably end up doing another rear end with