Originally Posted by
unterhausen
As explained to me after I asked a 'bent riding engineer what the OP is looking for, the tiller effect is having too long of an moment arm over the fork. This results in slow steering and makes control impossible. So for a long wheelbase 'bent, you can end up with a very slack head tube angle to make the moment arm shorter.
I have read about wheel flop and perhaps it's a factor as well. It's defined
here:
f = b sin ∂ cos ∂ *
Where:
f = "wheel flop factor," the distance that the center of the front wheel axle is lowered when the handlebars are rotated from the straight ahead position to a position 90 degrees away from straight ahead
b = trail
∂ = head angle
You could try plugging in some numbers and see if you can get something comparable to upright bikes? Trail = (wheelrad*cos(HA) -offset)/sin(HA)