best mule for roadracer..650 or 1000?

thinking about how fun it would be to build a track only bike....stacks, every tab removed, gussetted frame, total loss, ect. Just wondering which chassis would be the best platform to start with, ie, wheelbase and geometry. anyone with the stats I'd appreciate your feedback if you've looked into it or done it. not really concerned with the motor/power as the FIRST priority...but the handling.

ive allways been partial to 900-1000s,id use a 1000 frame .theyre beefier than 900 and its easier to make horsepower with the bigger motors and you dont have to worry about trying to make them fit the frame!goodluck,happy wrenching!

The 650 is the way to for Chassis rigidity. The 650 released in 77 included frame gussets and swing arm bracing that was added to the later KZ900 and KZ1000 frames.

Both frames are double downtube type and use the same diameter tubing. Put both frames next to each other and compare them and you will see the 650 is basically a 3/4 scale 900 frame. Pretty much the exact double down tube layout including tube diameters..

Now, we all know given an equal force applied to both ends of a tube, the longer a tube is the farther it will flex. The 650 frame has got be more rigid than the 1000 frame for this reason.

In his book Tony Foale suggests building a Jig to measure frame flex. Basically laying the frame on it's side secured via a rod through the swingarm hole. then placing a second rod throug the steering stem and hanging a 10lb weight 6 feet out on this rod. Then measuring how far the steering stem flexs. Anybody got a couple of frames laying around to run some experiments?

The only question then is how much power you can coax into that smaller chassis.

great thoughts here...anyone have the chassis geometry for both 650 vs. 900/1000?
wheelbase
rake/trail #'s

If you have the option I'd suggest a GPz750 Turbo frame, they have a larger backbone and are gusseted from the factory. I think they are the most ridgid fram Kawasaki made, at least through 1985.

But then you would have the monoshock, and it may not be legal for your class.

There are a couple of guys on the board that race, and I think they both run 650 or 750 Kaws.

i was in the garage the other day at a friends house and a friend of his came riding up on a 650 raggedy looking piece of of trash talking about how he whipped up on a 900 last week,and i asked him how many plug wires were off on the 900 he didnt like that too much,but he kept flapping his jaws about the 650 and 900 looking alike and how fast his was.i said ill be right back,my friend knew what was going on i went back home and grabbed the old 1170 and brought it over,sideways down the alley!:evil: when i pulled up i asked him if he was ready to bash em off with a bike with all the plugwires on ? :whistle: suddenly it was too cold out for him to ride!i parked mine next to his everything on his bike looked tiny next to mine including the frame,im guessing hi was a 77-78 it still had a tailpiece on it and wire wheels with disc brake on front!:whistle: goodluck,happy wrenching!

.............Rake/trail...................wheelbase
Z1.........27*/95mm(3.7in).............1491 mm(58.7in)
KZ1000.....26*/........................1505 mm(59.25in)
KZ1000J,K,M,P..27.5*/98mm(3.8in).......1520 mm(59.8in)
KZ750......29.5*/......................1420 mm
KZ650B and C..29.5*/108mm(4.25in)......1420 mm


While the 650's frame was similar in design to the Z1, the main backbone tube was 6mm larger in diameter with more gusseting and more substantial engine mounts. Surprisingly, considering the Z1's marginal swingarm, the 650's was constructed of even smaller tubes.

Post edited by: rstnick, at: 2006/02/02 22:24

great info, is it possible to bolt up the 1000 swinger onto the 650 frame without much 'fitting'? or is it a major mod? or what is the best bolt up swinger to use? BTW...like the paint design on the 650/Rickman tank.

The 650's handel better than the 900/1000's. For a stiffer swingarm you could fit a GPZ swingarm on then add some shock mounts.
Mark

we need to find a central location around here to do some testing like the magazines do .acceleration,braking, handling etc.give all bikes same tires o make that even no excuses.they have a roadracing course over here at mid america,with a dragstrip right next to it,anybody up for some testing this summer?ill bring the 1000 we need a 900 and a 650!:whistle:

thought my house would be surrounded with 650s by mow:whistle: must be the calm before the storm!bwaha:silly:

Wireman, Anyone with any ounce of sense knows the 900/1000 will eat a 650 in a straight line run. Maybe the 650 would do the same to the 900/1000 in the handeling. What about the best of both worlds and shoehorn a 900 into a 650 frame ? Gusset the frame to withstand the power of the 900 and make it possable even handle better ? I'll donate a frame , if wireman will send me a 900 motor complete with wiring and stuff.... LOL... Wayne....

P.S. Also Rob (rstnick) can send me that rickman fairing too... LOL...