Frame Geometry

To lengthen the forks:what about cuting the top tree fork clamps off a doner tree and grafting these tree fork clamps under the existing top tree fork clamps so you could slide your forks down?:side:

you could turn down the bolt for a 750 but on the 900 it was a little too short.
I Had a sleeve made up to go over my swingarm axle bolt to fill the gap (made it in 3 pieces for ease of drilling,zrx bolt was larger diameter.)

Post edited by: mark1122, at: 2006/12/31 11:39

Maybee I should just keep the old one. NOT. LOL.

What is the vest way to center the rear rim to the front? I tried a sting meathod I read on the net but I cant repeat consistant results.Then I tried a straight edge from front to back . That seams better ,but still some minor inconsistancies due to the distance and choise of staight edge.

Hey, here's something that I didn't do with my 'J' that I wish I would have (and I will do with my ELR clone) done is to weigh the components to see the improvement. A big difference that I expected was wheel weight; a big difference that I wasn't expecting was the weight difference in tires!

Anyway, you asked about rake numbers I note in your notes that your bike is 'raked'...that's going to take a little out of your length also. I am trying to keep the cornering ability with my 'J' bike so I did not modify the rake; and no I did not need a damper. As you can tell with your rear suspension setting there the rear is swapping a 17" for an 18", so yeah, it's only a 1" diameter swap, but note this: the side-wall of the 18" wheel in conjunction with the way the bias-ply rear tire is constructed combines to make the 18" wheel/tire combo pretty tall...so, the affect on the rear ride-height is pretty significant. Seemed to me like the rear was even lower than the front, but basically the whole bike came "down". Lean clearnece suffered a 'bit' but not as much as you'd think.
I can't tell you what the rake 'was' b/c the Ohlins are now in the ELR clone and I'll have to take my measurements when I get the ZX7/9 front end on that bike.

It's clear that you are taking a detailed approach to your set up and I just wanted to tell you that that approach is going to pay off for you.

Please keep the pics and info coming!
-KR

Thanks BadKaw .That is suprising that the new wider tires are lighter.My rake went from 26(stock) to 27.5 So this may help.I wont have to drop the back as much.It seems that 1" up or down at the back is about 1 degree of rake at the front.

Yeah, the tire thing is a 'construction' issue. Old Metzler, Pirelli, and Dunlop bias plys were "heavy" compared to the radials of today. An experiment that we did at the shop was to weigh some sport-bike tires to compare a weight difference that we had noted simply be picking them up. The Rennsports that we weighed against the 207s (you can tell we did this a couple years back) were a couple pounds lighter at the rear and more than a pound lighter at the front. It was a 'meat' issue; the 207 was a street tire and the Rennsport was (in my opinion) the first generation of real track-day tires and there was simply less material on it. Less weight, less reciprocating mass...yadda-yadda-yadda. Anyway, the comparison to bias-plys is even worse b/c of how they are made; at the same shop we installed HD Dunlops and you didn't even need to do a comparison there...lots more 'meat' and lots more miles.