I know a lot of people are running shorter forks for looks and such, and to each their own. I would like to add for those that may not be aware, if this is a bike you truly intend to ride at something other than a pedestrian pace, (sub 20mph) a short fork will almost certainly, eventually, lead to tankslapper condition which at normal driving speeds could easily be lethal.
When the wheel hits a bump, the forks absorb the energy on the upstroke and redirect it back down on the downstroke keeping the tire in contact with the road. If there is not enough fork travel to do this, and I think 4" is the minimum in my book, the energy travelling up the fork will bottom the suspension and the energy is then redirected sideways into the steering causing the steering to oscillate side to side. Your elbows will hit the tank on both sides, hence the term "tankslapper". It is virtually impossible to recover from this condition, the handlebars will be ripped from your hands, and you will go down.
Those of us who have raced, or ridden dirt bikes, have experienced this as we have overtaxed our front ends at one time or another. I hit a hole on the interstate on my GT650 Hawk, it bottomed out and the resulting tankslapper broke my finger with the clutch lever, (put your pinky finger on your desk, then take a clutch lever and hit it hard enough to break the lever and the finger, that's the kiind of power we're talking about. And that's before I left the bike!) ripped the bars from my hands and threw me down the road at 60mph. had a truck been following me it's been lights out, as it was on a section with sides and no where to go.
Our SOHC forks are pretty puny to begin with. Any reduction in their effectiveness is a safety issue, please proceed with care.
Whenever i see a bike with shortened forks, i just cringe.
