Originally Posted by
bautieri
If this is strictly your "go-fast" bike. I'd get the S2. The twichiness you feel is likely the difference in geometry and possibly a bit too much weight being supported by your hands. I remember my first road bike, coming from a mountain bike, I thought I would never get used to the handling. In time, I did and now I find the handling of most mountain bikes to be far to ponderous. Coming from your current bike, the twitchy feelings are probably similar as the riding position is more aggressive. If you find you can't live with it, a stem with a bit of rise in it would do wonders to get your weight back off your hands.
From the posts I've read of yours, you seem to know a great deal about bikes, and about how they work. Let me ask about this in more detail. I had thought the handling ( turning, mostly ) came from the fork and headset angle, and the wheel base. I think the R3 is set up to be faster than the S2 in both of these ways. But it sounds like the bar height has a lot to do with it - which is what the guy at LBS seemed to be implying when he said I should test ride a 61 cm frame if the 58 didn't handle well, because of the taller headset. And it made a lot of difference. First ... will using a taller stem when the bike isn't designed for it cause any problems with this? Second, if I wound up doing that, either for comfort or to change the steering, how would I figure out how much of the aero benefit I would give up? ( I guess test ride it with a taller stem? ) Also, if the R series turns more quickly and feels better for handling ... do I really
want to get used to (only slightly) more sluggish handling?