'76 KZ900 (ZRX1200R) Build

Sprocket alignment.
Counter-shaft and final sprockets should both be in the exact same geometric plane, without any deflection whatever in chain travel between the sprockets.




Wheel alignment.
While both tires should be rolling in the exact same direction, their center-line road contact patches need not overlap.



Good Fortune!

Harvey1327 wrote: I'm in the same boat as Streetfighter KZ.
I run a 5/8" offset sprocket and it to has only removed the paint on the frame.
It does run within 2mm of the tyre and frame. Also without a bearing support.
The motor is a 1327 and has been dynoed at over 125 HP.
The only problem I had was the spline on the sprocket was about 14mm and there is
only 8mm on the output shaft. This resulted in stripping the spline on both the
sprocket and output shaft. Also this increased the offset.
I have replaced both with the same sized sprocket and used a longer output shaft,
Which I was told came out of a 79' model.
The only difference is the spline is 14mm long.

i have a D&G 630 5/8" offset sprocket in my hand. it is 12.8mm thick at the spline.
Just adding info here nothing more.
hope its helpfull.

NakedFun wrote: Looking for opinions. New measurements show about .358" between the outside of the chain and the widest part of the tire with the 3/8" sprocket. Now the chain at it .99 degree angle is angled toward the tire...so that should improve slightly with the 1/2" offset Leon is making me. So with the sprocket at 1/2" that puts the chain with .092" clearance to the frame with that extra .125" offset. So if I were to take another .125" - .200" off the hub, that would increase my frame clearance slightly and leave me with approximately.158" of clearance at the tire. This would still leave me with the sprockets out of alignment by .140" over 27.3" chain span. This equates to .3 degrees deflection. Is this OK? If I took that much more out of the hub for a total of .340" that theoretically would only leave me .018" to the tire which seems close. The other option would be to go out to 5/8" front, which means frame interference for sure, but then drop what I need to mill extra out of the hub to .215" from .200". Thoughts?

Cory

personaly , i would focus on getting the 2 sprockets to align perfectly. since leon can make any offset, this should be easy. as far as which sprocket to move, it doesnt really matter that much. as u have discovered, there r pro's and cons at both ends. choose which ever 1 u feel most comfy with. if u choose a larger offset,u may be fine with a 180 tire. if u choose less hub, u may need a 170 tire.
i did booth and still ended up with a 170 tire. :lol:

i took 9mm off the rear hub.
my project.
kzrider.com/forum/11-projects/103381-76-kz900-upgrade

Well I also ordered up another offset sprocket from PBI and got the 5/8". With this, I can mill the hub enough to have "perfect" alingment, tire clearance and I will probable slice the frame and lay a "c" channel in or plate and weld it back in. I may not end up using Leons, but atleast I'll have the option.

Cory

Patton wrote: Sprocket alignment.
Counter-shaft and final sprockets should both be in the exact same geometric plane, without any deflection whatever in chain travel between the sprockets.

Wheel alignment.
While both tires should be rolling in the exact same direction, their center-line road contact patches need not overlap.

Good Fortune!

Patton,

I get it, but everything has a tolerance! Just trying to understand what that is. I would be willing to bet even some factory bikes have some sort of deflection in the chain alignment side to side. Either way, I ordered a 5/8" so I can get everythign perfectly aligned and keep my 180.... I apprecaite teh consideration.

Cory

NakedFun wrote: Well I also ordered up another offset sprocket from PBI and got the 5/8". With this, I can mill the hub enough to have "perfect" alingment, tire clearance and I will probable slice the frame and lay a "c" channel in or plate and weld it back in. I may not end up using Leons, but atleast I'll have the option.

Cory

sounds like u have all of the angles covered.
keep up the good work. this project is going to be a winner.

here is how sanctuary processes the chain line.










hth,leon

leon

Yep that looks about right....

Cory

531blackbanshee wrote: here is how sanctuary processes the chain line.

hth,leon

is that a temporary jig, i see welded into the upper motor mount, too keep it straight during the welding?

Do you need to modify the upper shock mounts for the wider swingarm?

Your sag numbers will dictate spring rates. I have ZRX shocks on my Z1 and have 0 static sag.

mark that is where they have welded the removable spacer that goes in between the frame and rear engine mount.should help stiffen it up.

all of the pictures i have seen of the sanctuary guys welding in frame braces they don't clamp or"jig"any of em :ohmy: .they just start tacking them in and rolling them around in the floor and weld em up.

same for braces on swingarms, .

they do have a cool jig for welding in the laydown shock studs,tho :whistle: .

leon