630 to 530 chain and sprockets on 1980 kz750

My 1980 KZ750H1 has the 630 chain and sprockets. The bikes due for new sprockets, and a chain. I'm thinking about changing over to the 530 set up.

What do I need besides the sprockets and chain ?? Are there any spacers needed to do this ?? Or do I just swap out the 630 for the 530 ??

The bike runs to high RPM's on the interstate for me. So I'm wanting to change the gearing, to deal with the high RPM's.

Right now I have a 13t counter sprocket, and a 32t rear sprocket. I tried to install a 15t counter sprocket on this bike, and it was to big. I wasn't able to install the chain, even after removing the little chain guard for the counter sprocket. So I will have to go with a smaller rear sprocket. Will two teeth smaller make a big difference ?? Or should I try to go even smaller ??

Sorry for all the questions.....

Thanks !!

i replaced my chain and sprockets last year. I went down two teeth on the rear and it dropped the cruising R.P.M.s by 250. I also had to buy two spacers for the front. Your best bet is to call Z1 and tell them what your are planing. They will set you right up.

The chain "pitch" is longer on a 630 chain compared to 530. The "6" references 6/8" between pins, or 3/4". With 530 it's 5/8" pitch. Because the 630 pitch is longer, you will need more links in your chain if you move to 530. The sprockets will also need more teeth.

Your current gear ratio is 32/13 or 2.46

The 630 13 tooth sprocket size (diameter) is halfway between a 530 15 tooth and 16 tooth. I think a 16 will fit your engine but please do some searching through the archives here to confirm for yourself.

2.46 x 16 = 39 teeth for the rear sprocket if you want to keep the stock gear ratio.

Since you want to reduce the cruising rpm's, you may want to go down two or three teeth in this instance. Z1 Enterprises is a good place to order chains and sprockets. By all means call them and chat if you want to confirm what's best for your application.

Good luck and hope this helps.

Thanks for your advice guys !!

I will call Z1 next week.....

OK, I ordered my new 16t counter, and 38t rear sprockets from Z1 today. I didn't order the chain because I have a good source to get that on the cheap.

How long of a chain will I need with this set up ??

Stock 1980 KZ750H1 with 16t and 38t 530 pitch sprockets.

Thanks.

I went with 530s 17/42 keeping the original ratio of 2.47

My bike almost the same: KZ750 H2.

Do you remember how many links your chain has ?? I'm trying to find out how long of a chain I need to order.

Thanks.....

skooterbum4real wrote: OK, I ordered my new 16t counter, and 38t rear sprockets from Z1 today. I didn't order the chain because I have a good source to get that on the cheap.

How long of a chain will I need with this set up ??

Stock 1980 KZ750H1 with 16t and 38t 530 pitch sprockets.

Thanks.

Someone please correct me if I'm wrong, but off the top of my head I'd say you would be good with a 110 link 530 chain. Might even be too long, but it's easier to shorten than to lenghten. Since you own both a 650 and a 750 it shouldn't be hard to check.

Your 750 came with 13/33 sprockets and an 84 link 630 chain while your 650 came with 16/42 sprockets and a 102 link 530 chain.

530 chain:

5/8" = .625" - .625" x 102 = 63.75"

630 chain:

6/8" = .75" - .75 x 84 = 63"

So the 630 84 link chain and the 530 102 link chain are almost the same length and the sprockets are almost the same size - what you need to check is if the distance between the countershaft center and rear axle center is the same on the 650 and 750. I believe they will be pretty close - if they're not, you'll have to convert the difference to link numbers (and remember that the difference will show on both top and bottom of the chain).

Thank you OnkelB !!!!!!!

That's just what I was needing to know.

530s 17/42: 104 links and feets perfect!

I appreciate the help guys !!

I just ordered a 110 link DID. Sounds like it should be a perfect fit.

Just for information purposes, converting my KZ750H from the factory 630 pitch sprockets and chain, to the 530 pitch.

I replaced the 630 pitch 13t counter & 32t rear sprockets, with the 530 pitch 16t counter & 38t rear sprockets, with a non o-ring 110 link chain

I ordered my parts from z1 Enterprizes, as suggested by members here. They were great to work with. I did not need any spacers for the counter sprocket on my bike. I got the DID 110 link chain from another source. I had to remove 4 links from the chain, (no problem at all), and I got what I was wanting, My cruising RPM's dropped about 500 RPM's running 65 MPH. Taking off from a dead stop is also no problems.

For me, this conversion was worth every penny, and the work required to do it.

Warning to others wanting to do this, if you have the factory exhaust, plan on messing with the exhaust to gain room to remove the rear wheel's axel.