76 KZ900 upgrade

The begining.76KZ900, 1135cc.,larger valves,cams,and carbs.
I will be adding a 2005 ZRX1200 rear end.Then front end latter.Spray can red.

zrx12 rear.

Post edited by: mark1122, at: 2007/01/04 17:37

I had to remove about 2mm.from each side to fit it into the frame.then I had a sleeve (3 pieces where easier to drill)made to fit over my swingarm axle bolt because it was a smaller diameter.I found that the rim was not centered to the front rim.So I had to have shims made, and remove material from a spacer to move the rim 5mm. towards the chain side of the bike.Next I ordered a 5/8' 630 offset front sprocket ,16 tooth (you need 1 more tooth to compensate for the 17" rim.) , and a 35 tooth 630 rear.Now I had to line up the rear sprocket with the front.I had 9mm.milled off the rear hub.There was a clearance issues with frame and chain. I heated the inside of theframe with a torch and sqeezed it with a c clamp to flatten the inside.I may Have to use a 170 tire as the 180 will probable hit the chain._

Post edited by: mark1122, at: 2007/01/04 17:44

Post edited by: mark1122, at: 2007/01/04 17:51

Post edited by: mark1122, at: 2008/03/03 11:48

I admire the fact that you are diving into the ole KZ to upgrade, so to speak, but why not just buy a complete ZRX1200R and have a front and rear that was originally engineered to function "as one" with a modern frame and motor?
Just curious.

neilage66 wrote:

I admire the fact that you are diving into the ole KZ to upgrade, so to speak, but why not just buy a complete ZRX1200R and have a front and rear that was originally engineered to function "as one" with a modern frame and motor?
Just curious.

What fun would THAT be?!
Kidding...but "Why buy,when You can modi*FY*"
I'm working on doing the same thing,but with ZRX1100 parts.My parts-list IS getting smaller,but with the Holliday season just passing,I'm gonna have to rethink the whole budget thing.
I only need a few more parts,and I should be good to go.Might not be this winter,but We shall see.

Mark...why did You go with the 630 chain,Bud?
Why not the 520 or 530?
Do They even make a 630 rear sprocket that mounts to the ZRX wheel?
Just curious.

neilage66 wrote:

I admire the fact that you are diving into the ole KZ to upgrade, so to speak, but why not just buy a complete ZRX1200R and have a front and rear that was originally engineered to function "as one" with a modern frame and motor?
Just curious.

yeah where would the fdun be in that?

I'm a killjoy...shoot me...shoot me now!

I think it would be fun to have a Z-rex...how about a 2001 1200R in blue? Yeah, that would work for me.

Yea . Modify,modify,modify. :woohoo:

I thought the same ,and I guess it depends on each person.I would love to have a new one but that would mean more cash up front.Some times its easier to come up with a bit hear and there for upgrades.And then there is the fact that no matter what I have I just NEED TO TAKE IT APART AND MAKE IT BETTER AND FASTER.

I went with 630 because the 5/8' offset is only $60.As it turns out I had rear sprocket allready,in my parts bin off another bike.

Note added in oct./08. if i were to do this again i might recommend a 3/8" offset sprocket. it seems lots of guys do this and it avoids frame clearance issues.
It may depend on the swing arm u choose. Just check all your clearances. Frame to chain, and chain to wheel. Then decide if u can get away with a 1/2",or 3/8” offset.
Some guy’s have reported that if u mount the rim off center to the frame it does not harm the handling.

This is the next step.May not be this winter thow, as I will rebuild my motor first.

mark1122 wrote:

I went with 630 because the 5/8' offset is only $60.As it turns out I had rear sprocket allready,in my parts bin off another bike.

Any issues thus far,with clearance anywhere,using the 630 chain,Mark?
And what bike did that 630 sprocket come off of,to bolt onto the REX wheel?

Oh and...the USD front end?...looks like crap!You should just give it to Me,Buddy.:whistle: