Z1 Sprocket change question

Regardless of chain size (pitch) or shocks or struts, the gearing computation is based on comparison between the ratio of front and rear sprocket diameters.

Chain size (pitch) will of course influence the number of teeth on sprockets of equal diameters. But it's the comparative sprocket diameters that matter, not the number of teeth.

Rear tire diameter is a factor in overall gearing.
Rear wheel size is not a factor.

Good Fortune !

Dunlop is one of several tire sites providing detailed info as to dimensions, including over-all diameters of different tire sizes.

Click > www.dunlopmotorcycle.com/default.asp

Good Fortune!

This and a :kiss: comes straight from the Fat Lady after personally speaking to Euclid.

Good Fortune!

This was an excellent topic, very informative.
Just love this forum.
Oh and give my regards to Euclid.

Buckeye73z1 wrote:

I have a '73 Z1-900 that was running a 42T rear sprocket on a 16" rear wheel and stock hub. I'm swapping to a '80 KZ750G 16" rear wheel and it mocks up perfectly, but the sprocket on that wheel is a 38T and obviously much smaller in diameter than the 42T that was on my Z1. If I buy a 42T rear sprocket for the '80 KZ750G wheel (the sprocket on the Z1 hub has a larger bolt pattern), will it be the same size as the 42T Z1 sprocket? Sorry if this is a stupid question, as this is my first time altering gearing.

Wow! what's the 1/8 mile ET's?
Did ya wonder why the thing was so quick.

Sorry, I have been there!
I put a 13 tooth countershaft on a stock KZ900 once when I was young. To drive it to "OHIO STREET", a place were everyone street dragraced in the 70's.
I was going 6,000 RPM's at 55 mph on the thruway.
Boy, those were the days.

So I haven't checked the front sprocket yet, but I measured the pitch of my chain and my bike has the 530 conversion done to it. From what I've read, the 42T 530 sprocket is equivalent to the stock 35T 630 sprocket. So that would explain why the bike didn't have much different road manners than stock. Does anyone know if the 530 42T rear sprocket for the '80 KZ750G is the same diameter as the 530 42T sprocket for a z1?

Buckeye73z1 wrote:

So I haven't checked the front sprocket yet, but I measured the pitch of my chain and my bike has the 530 conversion done to it. From what I've read, the 42T 530 sprocket is equivalent to the stock 35T 630 sprocket. So that would explain why the bike didn't have much different road manners than stock. Does anyone know if the 530 42T rear sprocket for the '80 KZ750G is the same diameter as the 530 42T sprocket for a z1?

it would certainly have to be, from a mathematical standpoint the same circumference = same diameter,

The key is matching the sprocket carrier to the sprocket. When previous owners swapped wheels out, they will have swapped the sprocket carrier as well.

The stud hole spacing and center cutout vary from bike to bike. The Z1 sprockets are very different from the kz750 sprockets.

If in doubt, take some measurements.

Center hole, the number of holes and the spacing.

Jeff.Saunders wrote:

The key is matching the sprocket carrier to the sprocket. When previous owners swapped wheels out, they will have swapped the sprocket carrier as well.

The stud hole spacing and center cutout vary from bike to bike. The Z1 sprockets are very different from the kz750 sprockets.

If in doubt, take some measurements.

Center hole, the number of holes and the spacing.

I think he's got that one Jeff he's asking if the outer circumference is different between to two models , which of course it wouldnt be considering he's comparing 530 on both. good call on the chain conversion BTW but ur the expert

To maintain gearing as close to the set up that was on the bike, I needed a 41T 530 rear sprocket (I changed from a 150/80/16 to 130/90/16 rear tire). Jeff, I just ordered this and some other odds and ends that I needed. My 2nd order in 2 weeks and many more to come...Z1E is a godsend in helping get this old beast back together. Thanks.