Dales rear swing arm is off a ZRX1100, I know I have the same basic setup. However, there is a company call MotoGPWorks that sells a exact S1 swingarm replica for about $1300.00 bucks. I found that the ZRX1100 setup is plenty strong enough, and raises the rear about an inch, thus slightly reducing the rake angle. I have about 3500 miles on my zrx1100 swingarm and I can definitively say it makes a huge difference in handling. I also, at the same time, increased the swingarm pivot bolt to a 20mm using a ZRX rear axle, it fits perfectly. I believe the last iteration of the twin shocker GPZ/J models frames are pretty dang good handling. Their biggest issue was the spindly rear swing arm (frame wise) and slop in the bearing to pivot bolt connection. Goes without saying the forks and rear shocks were lethal in stock form. I swapped out the rears for a set of zrx1100 KYB's, which are light years ahead of the stockers, the forks were re-worked with RaceTek springs and gold valve cartridge emulators. I re-worked the emulators to get a tighter seal and a progressive type high speed valve spring. I fine tuned the fork oil as well...this made a huge difference. These old forks have way too large oil passage holes, they require thick heavy oil to actually dampen. With emulators installed you can actually have high speed and low speed dampening.
JM2C
577Nitro
