February 3, 2014

By popular request – geometry geekery for Steve’s frame

A few people have bugged me to do a geometry post on Steve’s bike from yesterday. I’ve been slacking on those lately because getting ready to move, dealing with a 2 year old and a pregnant wife, and trying to survive the horrible air quality on the Wasatch front has taken up most of my time lately.

But I can’t say no to my “fans” (hang your heads in shame!) so here we go.

-69 HTA (assuming a 120mm fork with some sag – Steve can run up to 150mm if he wants), 66.4cm front center, and 97mm of trail.
-That’s a 72 degree seat angle and 61.5cm/24.2″ effective toptube for those who don’t want to figure things out using front center.
-31.7cm/12.5″ BB height assuming big fat 2.5 tires. A bit lower with smaller rubber.
-41cm chainstays (actual, 40.5 effective) and clearance for a 2.4+” tire (a DHF will easily clear with the wheel pulled back a bit). I tried to talk Steve into letting me mess with the driveline since this is a SS-specific frame and he doesn’t need/want a bashguard, but he opted to be a little more normal. Otherwise we’d have done 40cm or something.
-Built for a tapered, 120-150mm fork with a tapered steerer and a 30.9 dropper post. I tried to talk him into a stealth but no dice – he already has a non-stealth post and it’s hard to argue that a little less visual clutter is worth $300. Note that I usually do 31.6 for droppers but it’s just as easy for me to do 30.9 if that’s the size you prefer.
-To allow full insertion of the post and get enough tire clearance, I offset the seat tube forward onto the downtube – so on this frame the seat tube and BB shell never meet. A supertherm downtube provides plenty of beef to handle the load.

Steve picked out a really neat avocado-y green color with a low/satin gloss that looks much cooler in real life than in pictures, too.

RAL 6003!