If you rake the trees, without raking the neck, you end up in a negative trail situation, which equals death wobble at speeds greater than 30, or so I have heard. I don't have enough in the gonad departmant to actually try a negative trail bike. I believe what I have been told in that matter, more thorough coverage at http://www.chopperhandbook.com/neatstuff/index.html

If you rake the neck, considerably, then you can add rake to the trees to bring it back to "traditional" numbers, 2-4 inches of trail. otherwise you end up out around 10-12 inches with a 35-50 degree neck rake.

I did a little theoretical drawing for jpswino while he was trying to figure his out.
Keep in mind that a telescoping front end stops being functional around 40 deg, then it would be a better idea to go with a girder or springer that functions better at those rake numbers.

H.C.C.M.F. Local 6978
http://hondacb750parts.net