taller gear ratio?????

hey just wondering i have been riding my kz for awhile now and was wondering if there is a way to maybe make fourth and fifth gear a bit taller without really affecting the first three gears????? it just seems to be perfect on all levels but once into fourth and fifth they seem to rap out too quickly to me therefore not getting the full speed out of the bike???? any suggestions???:dry:


oh yeah for those who dont know my bike lol its a 650 b2 model. sorry brain fart!!!!! :silly:

Taller gearing will result in lower rpm throughout the range at any given road speed. But with less acceleration, and about the same attainable top speed and mpg.

Good Luck!

yeah i know the acceleration will be down a bit but all i want is it to be down in fourth and fifth i dont want to touch or have an affect on the others. like if i run third gear up to 9400 rpms and shift to fourth i'm instantly shifting into fifth and in doing that fifth is low in acceleration. i dont know maybe a bigger bike is what i need???? i dont like to mess too much with stock unless its a simple part swap cause i dont want to weakin the bike and have to replace all the seals and so on. you know the speedo says 140 but it should say 105 cause i haven't really got mine to go over that. i think if fourth gear was a bit taller it would help fifth through the power band??

chevyhead wrote:

yeah i know the acceleration will be down a bit but all i want is it to be down in fourth and fifth i dont want to touch or have an affect on the others. like if i run third gear up to 9400 rpms and shift to fourth i'm instantly shifting into fifth and in doing that fifth is low in acceleration. i dont know maybe a bigger bike is what i need???? i dont like to mess too much with stock unless its a simple part swap cause i dont want to weakin the bike and have to replace all the seals and so on. you know the speedo says 140 but it should say 105 cause i haven't really got mine to go over that. i think if fourth gear was a bit taller it would help fifth through the power band??

You can't change the gearing on only some of the gears. Changing the sprockets is the only way and it changes the ratio on all the gears.

Are you hitting 9000rpm in 5th and only showing 105 mph?

Just a thought; with the stock sprocket and counter sprocket and stock diameter tires the KZ650 should be very near 120mph at 9000rpm in 5th gear. If at 60mph your tach shows 4500rpm then 9000 rpm = 120mph. If at 60 your rpm isn’t 4500 then either your tach and/or speedo is wrong, the sprockets are something other than stock 16/42 tooth, the tires are at least a little different diameter than stock, or the clutch is slipping. What rpm shows at 60mph? Incidentally, Kawasaki offered a 17 tooth counter sprocket for racing (part number 13144-1009) that may give you a bit more top end, but as you noted, it will change all 5 gear ratios. I snagged one on eBay but haven’t tried it yet. Ed

I put a 17 on the front of my 650B and it dropped the 5th gear RPM by about 400 RPM according to the tach. It's effect on first and second was negligible as near as I can tell.

hey ed i know that when i am doing 60 its about 4600 rpm its close to what you said. i am not sure if the tires are stock size i'll have to look that up. i think i have a 19 up front and a 18 on rear... i might look up that other sprocket. i need to get another speedo cable the new one that cycle recycle sold me had the big end on the bottom and the reason was cause the one with the small end on it was too short so needless to say one day down a back road not too long ago i became cableless...

4600 sounds very close to normal. The difference could just be the size difference between a metric size tire like 100/90-19 front or 120/90-18 rear vs. the original "inch" measured tires. The metrics generally have a little lower profile which might explain the slight difference. Given 4600rpm @ 60mph, you should be hitting about 117 @9000rpm. Be careful in your experiments; at that speed crap happens very quickly. Ed

talk to robinson tranmissions...i dont think that is the company name ...some one here will know it....anyway he will make you an "overdrive 4th and 5th"
might be pricey though

irishwill wrote:

talk to robinson tranmissions...i dont think that is the company name ...some one here will know it....anyway he will make you an "overdrive 4th and 5th"
might be pricey though

Thanks. I've been thinking about this for my KZ1000 shafty...no sprockets to change out. A taller 5th gear would be ideal. the first 4 ratios are fine but the engine revs too high at speed. The 1075 kit has planety of mid range torque. 3,500RPM at 65mph would be ideal

ok yeah that could be lol i am not used to the differences yet with certain metrics so that could very well be the difference. i will be thanks!!!!!

irishwill wrote:

talk to robinson tranmissions...i dont think that is the company name ...some one here will know it....anyway he will make you an "overdrive 4th and 5th"
might be pricey though

www.robinsonindustriesinc.com/