78 kz650 530 Chain Conversion Questions

I am replacing the chain and sprocket anyways and was wondering about converting to a 530 chain while I was at it to save a little weight and money on the chain. I have been looking for possible conversions and found a rear sprocket (JTR 1478) that should fit based on the the hole sizes and pattern and the center hole. The stock rear sprocket is a JTR 1477. Also, for the front sprocket I found a JTF 512 to replace the stock JTF 513. The JT numbers relate to the JT sprockets website ( www.jtsprockets.com ).

What I am wondering is if I will need to make any type of a spacer to set the offset for the chains correctly? Or, if someone has done this a different way, what sprockets did you use?

Lastly, what is the largest front sprocket that can be run on the kz650D1? I would like to change the gear ration as little as possible, however I would like to make the front sprocket as large as possible to reduce chain wear.

Thanks,
KC

The standard KZ650 runs a 16 front sprocket, I know a 17 fits just fine but an 18 gets awfully close. The 17 seems to be the best choise among most members looking for less RPM's on the freeway.

Didn't all 650s come with a 530 chain stock?

You may be right:blush: , for some reason when I went to order the chain and sprockets the site came up with 630 for my bike. If it did, it certainly saves a lot of trouble with the conversion :dry: , and here I was hoping to save some money and weight. I'll have to go back and look again.

1981-83 KZ650 used a 630, all others were 530

I can't say for all KZ650's, but mine (1978 B2) certainly has a 530 chain!

I just switched to a 40T rear sprocket (42T is stock). Although it only lowers the revs by 5%, it makes it much more pleasant at cruising speeds, and the loss of acceleration is not noticeable!

RonKZ650 wrote:

1981-83 KZ650 used a 630, all others were 530

Listen to the 650 expert, he's absolutely right.

Maybe a little nit picky at times, but we grumpy old men have earned the right to be nit picky

Could measure from pin to pin to determine chain size.
630 is 3/4 inch.
530 is 5/8 inch.
630 and 530 are same width.
Good Luck!

Ok, I measured it and it is a 530. My rear sprocket is a 40 tooth and I haven't looked at the front yet. I may have been confused or misread something. It wouldn't be the first time . Thanks for getting me straightened out before I started trying too hard to buy the wrong sprockets.

You could probably get away with a 520, and certainly a 525 in a DID or EK ZVM. A modern 530 chain's probably overkill on a KZ750.

I run a z650 B2 -78 and it has 530 stock.

Limey,
I also switched to 17 (front sprocket), which dropped the rev a bit. Now I'm thinking of switching the rear sprocket from 42 (stock) to 40.

Has anyone done this and can tell if the bike still has acceptable power on the 5th gear?

/Martin

I swapped mine to a front yamaha r6 520 sprocket and a race spec aluminum zx7 rear 520 sprocket and that saves a little weight and looks a lot better imho. I order from an ebat store as a R6 package and had him swap the rear sprocket for a zx. don't know if the kz and gpz (see sig) are the same sprocket bolt pattern, but I think they are. Works great! Good luck!

Brandon