Replacing Front and Rear Sprockets Question

I'm running the equivalent of 15/33 on my KZ1000 although I'm running a 530 chain, so it's actually 18/40, which is the stock final drive ratio of 2.22:1 for the KZ1000LTD, with the 16 inch wheel. 15/35 was stock on the 18" rear wheel KZ1000A's. Even though I'm running the larger 18" rear wheel and at altitude that is robbing my power, I do not feel over geared, I'm still in 5th at fairly low speeds if I'm just short shifting and observing speed limits, if I kick it down and open the throttle wide it heads to the red line in a hurry.

Thank you everyone for sharing your thoughts and expertise, helps and gave me a lot to think about! I probably should have been a bit clearer in the why I was contemplating this. First off I would agree completely that this is already a very quick bike with a lot of zip off the line, that's no the problem and wasn't what got me contemplating this. This bike will rarely ever see triple digits, and until I do a total frame off resto and have touched every bolt and component on the bike I have no idea what may magically fail and come apart at the worst time imaginable. So along that thinking if most of my riding will be from 25-85mph and with the stock gearing being more aimed towards the top speed ratios I considered taking advantage of gearing meant more for the speeds I was planning on going. Coming from the car world a good analogy could be equivalent to the stock rear end gears being 2.96:1 like many commuter or salt flat vehicles are. I would have changed to something like 3.23:1 or 3.76:1 on the high end. Quicker off the line but can still cruise no problem. That being said after a bit more consideration and research it seems that even a few tooth change up in the rear could push me over 5k rpms cruising at 60-65mph which is higher than I want.

Soooooo, I will likely keep the stock gearing or at least very close to it and instead just switch over to 530 pitch chain and sprockets. I've reached out to a few companies in regards to pricing out a 530 conversion kit with 18T front sprocket and 15mm offset which is stock as per the diagram listed on the JT sprocket site for stock replacement gearing (630 pitch) and a 46T rear sprocket and matching 113 link 530 chain (114 or so is likely what it will come with standard) and waiting to hear back. In a perfect world I would like to go with Supersprox Stealth rear sprocket with gray/black outer steel teeth and gold center aluminum carrier with a DID X-ring gold chain. I think that would compliment the color scheme on the bike and pop without being too distracting.

Waiting for replies on my inquiries but will share what I find when I do get a response.

Thanks!
Brett

Had a 69 Chevelle with a 4.88 rear end and a beefed up 427 for a while before I got married..... lucky I made it out alive. :woohoo:

Brett- i am also looking for a 530 offset countershaft sprocket for my 810 cc drag bike the off set amont is 6 mm not 15 mm. 15 is the overall thickness of the sprocket. pbi has them for $40.00 in 17 tooth 1/4" offset. 172-530

kawi810 wrote: Brett- i am also looking for a 530 offset countershaft sprocket for my 810 cc drag bike the off set amont is 6 mm not 15 mm. 15 is the overall thickness of the sprocket. pbi has them for $40.00 in 17 tooth 1/4" offset. 172-530

Ahhh gotcha, thanks that makes more sense! So 15mm is total thickness but 6mm is the true offset, thanks for straightening me out there

The 1/4" offset and 17 tooth would work out just fine, so if I go to a 17 toot front countershaft sprocket, and if with 18 teeth I would normally need a 46 tooth rear sprocket. With running a 17T 530 front sprocket, what would the Rear Sprocket tooth count need to be at and how many links?


EDIT: Ness answered this already above LOL, it is 43 teeth, which means 113 - (4/2) - 111 Links

Thanks,
Brett

redhawk4 wrote: I'm running the equivalent of 15/33 on my KZ1000 although I'm running a 530 chain, so it's actually 18/40, which is the stock final drive ratio of 2.22:1 for the KZ1000LTD, with the 16 inch wheel. 15/35 was stock on the 18" rear wheel KZ1000A's. Even though I'm running the larger 18" rear wheel and at altitude that is robbing my power, I do not feel over geared, I'm still in 5th at fairly low speeds if I'm just short shifting and observing speed limits, if I kick it down and open the throttle wide it heads to the red line in a hurry.

My two 1977 KZ1000A1 factory service manuals list stock as 15/33. And I have a 94 link chain on mine.
Even my 14/35 combo, I had no trouble riding at +60-75mph freeway speeds. It's just +5000rpm in 5th gear wears on you when your riding buddies all live 18-20 miles away .... One way.

missionkz wrote:

redhawk4 wrote: I'm running the equivalent of 15/33 on my KZ1000 although I'm running a 530 chain, so it's actually 18/40, which is the stock final drive ratio of 2.22:1 for the KZ1000LTD, with the 16 inch wheel. 15/35 was stock on the 18" rear wheel KZ1000A's. Even though I'm running the larger 18" rear wheel and at altitude that is robbing my power, I do not feel over geared, I'm still in 5th at fairly low speeds if I'm just short shifting and observing speed limits, if I kick it down and open the throttle wide it heads to the red line in a hurry.

My two 1977 KZ1000A1 factory service manuals list stock as 15/33. And I have a 94 link chain on mine.
Even my 14/35 combo, I had no trouble riding at +60-75mph freeway speeds. It's just +5000rpm in 5th gear wears on you when your riding buddies all live 18-20 miles away .... One way.

Hey Mission,

Thats what I am worried about is that 5000+rpm for 20+ miles... at stock gearing this thing cruises beautifully below 5000 rpms in the low to mid 4000 range. I think that changing to 530 pitch and going with 17T and 43T rear with 111 links will keep me very close to stock gearing its maybe just a touch quicker off the line. Sounds like that will be the best of both worlds, keep my cruising speed low so I'm not wrapping the sh!t out of the engine but with the lighter rotating mass and slightly "taller" countershaft sprocket will still be a bit more responsive down low.

When I combine this with the new igniter that I am trying to source with a slightly different timing curve the low and midrange will wake up a bit and help boost the low and midrange on these bikes.

Thanks,
Brett

:lol: I was at a rest stop in the Mojave and was getting ready to hit the FWY when 5 Ninga style crotch rockets passed by screaming. I caught up with them at 70. I was at 4000 RPM and they must have been at 6 or better at 60 in the slow lane. They didn't even look at me as I cruised by. :whistle:
Steve

swest wrote: :lol: I was at a rest stop in the Mojave and was getting ready to hit the FWY when 5 Ninga style crotch rockets passed by screaming. I caught up with them at 70. I was at 4000 RPM and they must have been at 6 or better at 60 in the slow lane. They didn't even look at me as I cruised by. :whistle:
Steve

Modern liquid cooled engines can sustain some pretty high rpm's without seemingly suffering ill effects. 40 year old air cooled engines are most likely better treated with a little more care for continuous rpm use.

I don't think many crotch rocket riders are really into bikes in the way we are, I literally look at every bike I see out on the road, even Harley's - it's either that or you were going so fast you were just a blur.

Well bit of an update here to clarify a few things now that I have been able to get back on the bike and ride her again.

So with the current stock 630 chain setup and 15T front and 38T rear sprocket I end up cruising at 60mph at 4000-4100 rpm's which is just awesome and so easy on the rider and bike. At 70mph I am hitting about 5000rpms dead. It still has a ton of zip off the line but I really don't want to give up the ease of cruising and how nice the lower RPM range is. I think going to a 17T 530 pitch front sprocket with a matching 43T 530 pitch rear sprocket will alter it very nominally and stay MOSTLY in the same range that I currently have. I suspect it might raise it 100-300 or so rpm's with the slightly "Taller" front gearing which will have a noticeable seat of the pants affect on acceleration off the line, but will maintain a mostly stock gearing with all the benefits of the 530 chain making it quicker and a bit snappier due to the lighter reciprocating mass and slightly taller front gear.

So that being said, unless some new information comes to light I likely will end up with a 17T 1/4" offset 530 pitch front sprocket from PBI, a 111 link 530 gold X-ring chain, and now just need to source a 43T 530 pitch rear sprocket that will fit correct on my NA 85 GPz750. If anyone is able to help locate the rear sprocket that meets these specs truly would appreciate it!

Thanks,
Brett

just bought a 17 tooth 530 for the 810 cc drag bike and a 50 tooth 530 rear that comes out to a 2.94 ratio. great for drag racing . 17 - 43 = 2.52 15 - 38 = 2.53 just about the same . the higher the ratio the lower it is geared. the only rear sprocket i could find where from pbi and they are aluminum .not my first choice steel lasts 3 times longer.

kawi810 wrote: just bought a 17 tooth 530 for the 810 cc drag bike and a 50 tooth 530 rear that comes out to a 2.94 ratio. great for drag racing . 17 - 43 = 2.52 15 - 38 = 2.53 just about the same . the higher the ratio the lower it is geared. the only rear sprocket i could find where from pbi and they are aluminum .not my first choice steel lasts 3 times longer.

Thanks Kawi810!

I would love to do a Supersprox Stealth one, when I get a bit closer to converting I will be calling them and seeing what it would cost to have one made up for me, who knows might already have something available and wouldn't have to go custom but we shall see. I like the weight of aluminum but durability isn't good enough as you said, see this as a best of both worlds deal.

Brett