If a track is designed on any mathematical model (rather than just "pile a couple berms and pave between 'em"), as most good tracks are, a target speed is picked, which determines the angle and curvature of the bankings. A bike will naturally track on the pole at that speed with essentially no steering required. At that speed, it doesn't matter what your front-end geometry looks like -- you'll have no steering problems on the pole line. This only applies to riding on the pole (or, on a really well-designed track, parallel to the pole at any point on the track); if you are riding anything other than a parallel line, you'll be back dependent on front end design.
Now, tracks have speeds picked for peculiar reasons. Trexlertown, for example, was intended as a community facility with a strong education and youth focus, so it was designed for a slower target speed (slower riders being the intended subject for design criteria). Consequently, a fast Cat I rider will have trouble staying on the pole because he'll be riding faster than the target speed. (This is why Trexlertown doesn't generate the kinds of times for the best riders that other tracks do.) This is where front-end geometry becomes important. If I ride at a faster-than-target speed on that track, I'll need a marginally more responsive front end so I'm not fighting the track; if I go too responsive, I'll tend to dip down. If it's a track with a very slow designed speed, I might need even more front-end responsiveness on the bike, although that would compromise my riding on some other tracks. Consequently, a capable track rider benefits from a front end designed to the specific geometry of the target track itself. A bike like the Look KG496 Athene is designed around Schuermann track parameters and current world-cup speeds (its front end was actually redesigned slightly from the KG396 because speeds had increased so significantly from when the 396 was designed -- that's the major contribution gained from the new model). And since most Olympics, World Championship, or World Cup events are scheduled onto tracks designed by Schuermann or following his principles (and designed for high speeds), one bike will work exceptionally well for all these tracks. A KG496 is not a great bike on a tight Belgian six-day track, which is part of why the European six-days are ridden mostly on aluminum frames which can be designed around the peculiar geometries of those tracks.
Practically speaking, a fast competitor can go to a slightly lower offset and take advantage of it when he/she is going faster than the track's target speed (which is the point of racing anyway), plus it'll generally help with maneuvering on the track. On this latter point, just watch a sprinter in trailing position going about 22-24 mph at the top of the track and then launching a drop down to the pole and an acceleration up to 35+ mph, all within the distance of the last banking. The centrifugal forces acting on that rider, and the very extreme abnormal weight distribution in those maneuvers make it very hard to steer that bike -- it'll feel like the headset is welded together -- so a very short offset and twitchy front end won't feel that way when you're actually racing. It's interesting watching new track riders on such bikes -- they are difficult to handle at low speed, but when maneuvering at speed they feel just like your typical road bike on a country road.
Last edited by 11.4; 01-02-06 at 02:50 AM.