Originally Posted by
burnthesheep
Yeah. I started a topic on Slowtwitch about it and several posters "it's a pig for cross". Then someone actually looked at the geometry I posted and was like "wait, it's not much different at all". Shorter chainstay, headtube angle pretty darn close, only 2mm different BB drop. Easily cured with 170mm crank arms.
I'll try it out, can always just keep the cross bike for literally only cross duty if I need to. Then if the cross course is really dry/fast roll the 3T.
The 650b wheel size would throw a variable that I haven't really experienced. However...
There are two aspects to slower handling bikes, at least that I've experienced, plus the BB drop thing.
So chain stay length definitely makes a bike feel different. Shorter stays make the bike more lively when out of the saddle (virtually no difference while in the saddle), and put more weight on the rear wheel in general. The slack seat tube angle adds to that weight distribution effect, means you'll have a lot of weight on the rear wheel. Maybe great for a steep hill with loose conditions (weight on rear tire = traction, but you might lift front wheel on steep hills), maybe not as great for comfort. I have a frame where I had the stays shortened so the front end was the same, parts were the same, just the rear triangle was shorter. Shortening the stays (1.3 cm) made an enormous difference in how it felt out of saddle, super snappy. Made it much easier to keep weight on the rear wheel in corners (prior to the shortening, the rear tire was chattering/skipping/sliding across pavement even in the dry). And the final thing, the turn in really felt no different, because....
The front end was the same. Head tube angle really affects the turn in feel. Trail is related to stability (no hands etc), but HTA really affects turn in. Because I generally ride 50 cm frames, I've ridden road bikes with HTA from 70.5 to 73 deg, and the responsiveness of the 73 deg HTA is amazing compared to, say, a 72. Similar if not identical trail, although I don't have exact differences. And since I tend to move parts from bike to bike, the wheels/tires would have been the same moving from one frame to another. Once I experienced a 73 HTA + 43mm rake I stuck with it, and even based my custom frames around that front end. The shallow head tube angle made it feel like the wheel was tilting more, not turning. For me the most vivid difference was when I was sprinting - I could instantly change lines as needed, whereas the shallower head tube angle felt like I was driving a jet ski, and I had to sort of start the turn and then wait for it to "set" and actually start turning.
More BB drop makes me feel like I'm "in" the bike, versus being "on" the bike. Like the BB is glued to the pavement. The higher BB bikes I've ridden have felt more "topple-y". My most extreme examples were my high BB mtb vs regular BB mtb (Cannondale sold a high BB, short stayed frame for a while, for "northeast logs and single track"). The high BB bike *was* better over logs, but it was so topple-y I toppled over at some point riding around my parent's yard and broke the (non-replaceable) hanger.