Wold Ranger wrote:
Maybe I understand this more than most, being from a precision engineering background. But castor and axle lead, both play an important role here too. The trouble is every damned fork has a different level of castor and axle reach, not to mention crown reach. It's the frame manufacturers that have the problems to solve.
This affects the handling dramatically. Some forks have no Castor, being parallel or in line with the headtube. others run forward to the axle at quite an angle. Fork crown profiles are widely different too. Some are angled well forward so the stanchion crowns are pitched in front of the crown race at varying degrees. Then there is axle lead, this varies from zero, and in the extreme 30mm plus. A ponderous steer effect is down to the axle being placed too far back, i.e. back nearer the crown, there is an optimum for each frame, accrding to head tube angle, so different forks will work better or worse. Interestingly enough fork manufacturers don't declare these numbers or adhere to a standard, which they should. Changing or upgrading a fork therefore, despite spending a fortune, can end up with a worse handling bike!
The whole subject is a can of worms.
Yes, according to the Kona catalogue the Project 2s on the Hahanna and Fire Mountain used to be different from the ones on the bikes from the Lava Dome upwards, with 1.74 inches of offset for the 'entry-level' rider and 1.54 inches for the Lava Dome upwards. So obviously 0.2 inches on the offset must make a palpable difference in steadying up the steering, otherwise a bunch of cheapskates like Kona wouldn't have bothered with it. My general impression is that most (at least xc) suspension forks do have offset around 1.5 to 1.6 though.
Isn't there quite a lot of significance also in the way that the head angle affects 'trail', which is the distance between the centre of the tyre's contact area and the point on the ground that the steerer is pointing at?