So, which offset sprocket is best for 160mm tire?

Gettin' parts together for my Z1. Which front sprocket to most guys run here when going with a 160/17 tire?

CruisingRam wrote:

Gettin' parts together for my Z1. Which front sprocket to most guys run here when going with a 160/17 tire?

Lining up with the rear sprocket seems the most important goal to me. Is that sprocket offset from stock?

Well, typically, so far, I have had to buy an offset sprocket, and had to have a spacer for the rear sprocket- and then play wiht spacers- but I can't remember which one I bought last timeB) Been about a year and a half ago I think.

And it was for a ZX10 rim though, with a 180, and I am running a 160 this time.

I have a 160 tire on my 1000 and used a 5/8" offset. I've heard guys get away with 3/8" as well. It all depends on where your rear sprocket ends up. I was lucky enough that I bought the 5/8" front sprocket and when I got the swingarm and wheel in everything lined up. But it's not going to be that easy all the time.

Later, Doug

StreetfighterKz wrote:

I have a 160 tire on my 1000 and used a 5/8" offset. I've heard guys get away with 3/8" as well. It all depends on where your rear sprocket ends up. I was lucky enough that I bought the 5/8" front sprocket and when I got the swingarm and wheel in everything lined up. But it's not going to be that easy all the time.

Later, Doug

Thanks man- is it ever easy?

Do you have the new rim now? If so you can always measure from the center (or as close as you can) to the sprocket mounting surface. Then do the same thing to the stock rim. Subtract the two and that'll give you a rough idea.

Later, Doug

Oh my lord- hadn't even thought of that- too easy! :ohmy:

SteetfighterKZ,

Sorry for my old man ass ignorance where I have to ask!

You got my interest up for I've been wondering the best way (accurate measurement) to figure this out as well but I'm not sure I'm fully understanding your description.

Measure from the center to the sprocket mounting surface?
Does this mean measure from the center of the OEM counter sprocket in comparison with the exposed output shaft length that the counter sprocket is connected?

Or does this mean measure from center or engine to center of counter sprocket?

Same thing with stock rim?
Does this translate measure from center rim to center of rear sprocket?

Again, sorry for ignorance here just trying to understand more clearly.

BTW, my project is KZ900 modification with ZX6R rear swing arm, 180mm tire.

Thanks,

Old Man Rock

Old Man Rock,

All the items connecting to the engine will remain constant. What changes is the position of the rear sprocket. Usually it moves away from the centerline of the frame.

I made a quick diagram to make it a little easier for everyone. Simply take the "blue" measurement and subtract the "red" measurement and that will tell you roughly how far the chain line will move away from the centerline of the bike.

If its 0" to less than 3/8" you might get away with using a stock front sprocket and machining your rear sprocket carrier.

If its 3/8" or greater but less than 5/8", you'll probably have to get a 3/8" offset front sprocket and possibly machine the rear sprocket carrier.

If its 5/8" or greater difference you'll need a 5/8" offset sprocket and possibly machine the rear sprocket carrier.

If its alot more than 5/8" i.e. 1" or so you'll have to do some major engineering because the chain will want to occupy the exact same space as the frame.

Obviously those are just guidelines. You might be able to use a couple washers behind the rear sprocket to take you to the next bigger offset front sprocket but it's kina a case by case scenerio.

Hope this helps.

Later, Doug

Post edited by: StreetfighterKz, at: 2008/02/02 12:57

Excellent, thanks!

Do the same from center of motor since the tire is lined up and subtract your two measurements and WHOLA!

Again, thanks for the clarifications.

Old