Correct trail is somewhere between 5-13 cm, depending on if you have a rigid frame or a swing arm frame. You can never know exactly, Correct trail is essential for optimum ride!!
# 1) Hold the measure tape from the front wheel axle and vertical down to the floor. Mark the spot.
# 2) Place the tape parallel to the steering axle, following the angle of the steeringhead all the way down to the floor. Mark also this spot.
Measure the distance between the two spots – this is your trail!
A suitable measure for rigid frames and choppers is between 5-10 cm. If you have a standard bike with rear suspension, the trail should be between 8-13 cm.
Scrambler: Rake 27.8º
: Trail 105 mm
Every change you do on the geometry of the bike will have effect!
but i think with small changes and doing both the front and back you will be good....
My Bonneville 2001 have 11.5" rear shocks (292 mm)
and I lowerd it 2" front... (Big change!!)
12000 Km this summer without any bad experience.. It handles like a dream!!!
Ps. the photos and text is from...
http://tolle.se/index.html?lang=eng
Our Swedish fork and trippeltree GURU! .ds
good luck with you bike
