Foot touching front wheel?

where

Offset-- Centerline of top of steering neck to centerline of top of fork tubes.
Rake-- The angle in degrees of the steering neck from the vertical.
Fork Length-- The distance between the top of the fork tubes to the centerline of the axle.
Diameter of the front tire.
Diameter of the rear tire.

............. blah ....... blah ........

Got an excel sheet for this.
You want it ?