If you have a trike with negative front camber, or there is toe or camber change with suspension movement, setting the toe by the traditional measuring method can be very difficult to get right - where 'right' = minimum rolling resistance at typical ride height.
But - and maybe everyone already knows about this but I didn't - there's a very easy way to do it.
Connect one tie rod and leave the other off at one end (eg the outer end). Ride along slowly, going straight ahead. (That is, steer straight ahead with the one connected wheel.) The disconnected wheel will track truly. Stop without further changing the steering.
Adjust the tie rod length so that the disconnected tie rod rose-joint matches the position of the wheel. On my trike, with a vertical threaded spud, I adjust the free tie rod length so that the rose-joint drops straight over the spud.
My minimum rolling resistance actually looks to have toe-out (I run neg camber).
