TOPIC:

I know that this has been gone over several times before (I did a search in the forum). But I can't find the answer that I'm looking for. The project I'm working on is a 1981 KZ1100 shaftie frame with:
1982 kz1000 motor (chain drive)
1979 kz750 twin front forks and wheel/brakes
1981 xs650 yamaha triple tree
198? honda vlx600 swing arm and mono shock
19?? yamaha R1 rear wheel (6" x 17" with a 190 tire)

Those are some of the basics on this build. The reason for the shaft drive frame is more room, so I didn't have to modify the frame for a wide tire (that and it was cheap).
I bought a 5/8" offset sprocket from PMF, and have a 530 chain (tsubaki), going to run the R1 rear sprocket.
I made the appropriate spacers to fit the swing arm in the frame and am try to get everything in line, the wheel is offset to the right 3/8" (can only go over to the left about 1/4" before the chain hits the swing arm). With this setup my 5/8" offset sprocket needs to go to the left an additional 3/16" to be in line with the rear sprocket.
So on to the question, where am I going wrong. Is it ok to run the rear tire 3/8" offset to the right? Should I order the 7/8" offset sprocket? I'm a machinist and can make any spacers that I might need to get this project done.
Your help, and comments are greatly appreciated

I'd think if the front and back wheels don't track in a straight line together,driving will be,lets say, interesting.

I laid a staight edge along the back wheel and measured the distance from the front wheel to the straight edge, on each side of the bike, and came up with the 3/8". I also leveled the bike from side to side and dropped a plumb bob from each side of the frame, at the rear wheel, also came up with 3/8". From what I've read here and on other sites, I didn't think that having the rear wheel offset would be such a good idea. Just not sure how to make it all work. I've been working on this for awhile now and kind of at a loss.
Thanks agian for any input, kz1000j

Actually, as understood from timebomb and others, several new models, especially Harley, have a fat rear wheel with centerline not exactly same as the front wheel. And as I recall, maybe an inch or more offset from the front wheel straight line track.

In other words, both wheels are rolling in exactly the same direction when the bike is moving forward in a straight line, but the centerline track is not exactly the same for both wheels.

The centerline tracks should of course be parallel when the bike is moving forward in a straight line.

Instinctively, it would seem that the best situation would be having an exact same centerline track for both wheels when the bike is moving forward in a straight line. And I always thought so until recently upon hearing from those more in the know.

Perhaps a roadracer may yet to this day prefer having the exact same centerline track when the bike is moving forward in a straight line.

Am thinking my bikes (Z1, KZ900 and Honda GB500) each have wheel alignment with exact same centerline when the bike is moving forward in a straight line.

Am guessing it won't hurt to have the 3/8" offset in the case at hand, even though the KZ1000 wheels likely had the exact same centerlines with the bike moving forward in a straight line.

Meanwhile, please await more positive advice about this.

Good Luck!

"Is it ok to run the rear tire 3/8" offset to the right? "
Personally, that wouldn't be ideal for me and at the speeds your most likely to hit with your motor build why risk it...

Should I order the 7/8" offset sprocket?
Most probably going to be custom made due to the only 7/8ths I've come across where 630 pitch only...

Also, keep in mind, this has to tuck under the clutch cover.... Even with a 1/2" off set sprocket, we all had to grind some of the internal cover away....

PM Mark1122... (Mark Saunders) for he had his rear sprocket hub milled down to match the alignment... His project is somewhere in the Project files...

Being a machinist, you should be able to do the same... May have to drop down to a 180 rear tire, who knows...

OMR

ZRX1200 rear wheel is offset about 15mm from the factory. It is a reasonably quick bike and seems unaffected by the offset.

Having everything in line would be ideal but years ago, one of the ways they used to put wider tires on these Z's was to widen the right side only of the rear rim. Made the rim about an inch or so wider. Now I don't think they were road-racing with these but it used to be the only way to get a wider rim. This was before offset front sprockets and such, but many bikes ran like this. Personally, I would want mine lined up but it will work if the rear is off-set a little. Problem is knowing how far you can go before it gets too bad in the handling department, but it would be trial and error at that point.

When I was measuring to put the R1 swing arm in my frame I did consider milling the sprocket carrier down a bit. It looks like there is about a 1/4 inch of material that could be removed from there. If you look you will see the sprocket is riding on a set of standoffs.

This is what I am going to use.

www.kosman.net/page14.htm

I had to spread the frame apart to fit my swing arm, this was advantageous because now I do not have to worry about frame to chain clearance. I was able to center my rear wheel inline with the front.

there are more bikes out there than you might believe offset.i have heard that there are certain years of gsxr's that are offest 3/4" from the front.
i can tell you that my z1r is offset 3/8's to the right with a 190mm wide tire(previously a 200mm)and i can feel absolutely no difference in turn in right or left.running down the road at 70mph i can remove my hands from the handle bars and it tracks straight as a string.
that's my experience anyway.

leon holmes

this is with the 200mm wide tire.

you can kinda tell here.although no one that i haven't told has ever noticed.tire wears even also.

leon holmes

Thanks for your input 531blackbanshee, it's good to know that some of you guys are running the back wheel offset with no problems, might end up doing the same. Last nite I did some more measuring, and this is what I came up with.
Measured from centerline of rear wheel to outside of wheel sprocket on my stock 82 kz1000. Then the same on the 6" wide R1 wheel, (I had already milled 1/8" off the sprocket carrier on this wheel), and came up with a difference of 7/8". So based on those numbers I would need the 7/8" offset front sprocket. I've also already made an outboard bearing support for the front sprocket (can shoot some pics if anyone wants). I would like to have the back wheel in line with the front if at all possible. By me using the shaft drive frame I didn't have to modify it, just made spacers to fit the swingarm.
Thanks, Chris

put your wheel in your swingarm and pull a string off the back side of your rear sprocket to the front countershaft sprocket and see where the front want's to be.i was trying to get all technical with mine with lasers and $h!t and this redneck i work with goes "hell we just use a string".i centered my hub in my swingarm when i was building it and then found out later that the tire wasn't centered over the hub.oh well rides fine and i got away with a 3/8's offset countershaft sprocket running 520 o-ring chain.

leon holmes