progress/problems 5/8" offset sprocket 190/gsxr

How the bike looks as of 6/26/08



progress: here is some info on my recent progress. I finally got my sprockets ordered. I ordered a 45 tooth 530 sprocket for the rear, and I ordered a 5/8" offset 17 tooth 530 front sprocket. I ordered the offset sprocket from www.pmfronline.com , btw their service was great and i was very impressed with the product. Still need a chain, but it looks like once I mill down the rear sprocket spacer(hub) the chains will line up great with no chain rub on the frame. I know many of you have had problems with the chain hitting the frame, but i am very confident i have plenty of clearance (1978 kz650 frame).

problems: I will post some pictures down at the end of the post. My left side engine cover ( chain cover ) no longer fits because of the size of the offset sprocket. There seems to be a lartge amount of material on the outside that is unneccessary. Would it be okay just to cut this off? When milling down the hub, do you need to machine some kind of a spacer to fill in the space that was removed, or is there an easier method?





Sprocket clearance

I wouldn't hesitate to cut off that extension on the countershaft sprocket, I can't see where it's doing you any good by being there.

When milling down the hub, do you need to machine some kind of a spacer to fill in the space that was removed, or is there an easier method?

I don't understand what you're asking, when I milled the hub I just removed 1/2" behind the sprocket then shortened the sprocket mounting bolts. But I used a Suzuki GSX750 wheel and don't know what you're using.

I did have to make spacers that fit over the axle to center the wheel in the swing arm I'm using (83-85 GPz750). I made the spacers out of titanium simply because I had some on hand.

5/8" offset? Are you using a 180 or 190 tire?

that sprocket appears to be for use with an outer bearing support. pmfr sells em too i believe. either buy that, or call pmfr and tell em you need a offset sprocket without the nose-because you're not using an outer bearing support. dont cut it off until you call them. its un-used and pmfr is a gd company. they should exchange it for you.

Not to be a downer, but I constantly hear ppl complainng about big tires and clearance.

I have a 190 rear on my moms 77 KZ 650 and have clearence issues other than having to remove the centerstand. lol


steell wrote:

I wouldn't hesitate to cut off that extension on the countershaft sprocket, I can't see where it's doing you any good by being there.

When milling down the hub, do you need to machine some kind of a spacer to fill in the space that was removed, or is there an easier method?

I don't understand what you're asking, when I milled the hub I just removed 1/2" behind the sprocket then shortened the sprocket mounting bolts. But I used a Suzuki GSX750 wheel and don't know what you're using.

I did have to make spacers that fit over the axle to center the wheel in the swing arm I'm using (83-85 GPz750). I made the spacers out of titanium simply because I had some on hand.

5/8" offset? Are you using a 180 or 190 tire?

Sorry, forgot the pic.

dreamsofaz1r wrote:

Sorry, forgot the pic.

Is that a stock wheel and Swingarm? ive got a 130 on a stock 16 inch wheel and there is only a quarter inch on either side between the wheel and the swingarm?

dreamsofaz1r wrote:

Sorry, forgot the pic.

lol i hope that was a attempt at a joke, cuz thats not a 190

lol i hope that was a attempt at a joke, cuz thats not a 190

No kidding, can you imagine a 190 mounted on the 3" wide rim pictured? If I recall correctly the 190 requires a minimum 5.5" wide rim :laugh:

And a 190 won't fit in a stock 650 swingarm.

I have a 160 mounted on my KZ750E, 4.5" rim and GPz750 swingarm, and it's huge, but not as big as the 190 fitted to my Nephew's KZ650 on a 5.5" wheel and GSXR swingarm.

Maybe he meant to type "140"

Sorry to hear what your running into.... As mentioned in another posting regarding the offset cc sprockets, this was part of the concerns with a 5/8" offset.

call pmfr and tell em you need a offset sprocket without the nose-because you're not using an outer bearing support.

I had contacted PMFR and didn't get much help with the lady I spoke with. When I informed her what I was looking for (530 without a nose) she replied they did have 530's in inventory but with a nose only & they would not cut it off. Nor did she offer that they could make one without a nose. All in all, disappointing conversation.

The in my recent (again disappointment) with Kosman Specialties, they sent me a 530 15 tooth to check out but no way, chain is going to beat the crap out of the pivot tube. I have since wrote numerous e-mails on whether they can make one or what was the next move, no replies. I have sent the sprocket back and don't have a warm feeling that they're going to do a damn thing.

All in all, went with the 13.5mm (>1/2") 630 offset from Americanclassix.com. I realize some of you have had dealings with them but so far I have had pretty good luck with them, no issues to report on any of my previous orders. Same time, somewhat out of options for Pingels & Ape only offers 630 5/8" offsets....

Sometimes old man rock thinks to himself, WTF did I get myself into! :blink:

Hope it works out for you,

Old Man Rock

i got my offset sprocket from MRE, and their service was great. they didnt have what i wanted in stock, but they had no problem making it.

the original poster mentioned he had a gd experience with pmfr, so theres no reason to jumpship for him. also, if you have the cash to spend, and you're gonna be making some major hp, an outer bearing support is nice to have. personally i think they look better than the stock cover anyway.