Front Sprocket Bigger?

I read on another topic forum about increasing the front sprocket one tooth for lower RPMs at highway speeds. My 77 KZ650 B1 has a 16 tooth stock sprocket,I plan to do most of my riding on the highway and I didn't know if its feezable to do. I know it will be sluggish at slower speeds,but I like to keep rpms at a low speed not to lug it. Whats your input. Yea or nea..?? or Smaller in the rear??:blink:

Here's agood website to help figure chain speeds and engine rpm's:
www.gearingcommander.com

One tooth on a 16T is only about a 6% change which is pretty negligible. For example, if you presently spin 5000 RPM at 70 mph, that change will drop you all the way down to 4700 RPM... not much gain.

Should be no problem.

Mark

A 17 tooth sprocket comes close to the chain guard but does fit. My 650 with 16/42 gearing (stock) buzzes about 5800 @ 70mph, The 17 should drop that to about 5500 or less with minimal effect on normal acceleration.

Can do. Kawasaki actually offered an optional 17 tooth engine sprocket (part #13144-1009). I have one, but I haven't tried it yet. I may do so next time I change the sprocket/chain set, which at the current rate of wear might be 10 more years :laugh: Ed

One place that sells the Stock 16 tooth gear says the 17 tooth was only for racing,

Speak of the devil! Here;s an original 17 tooth KZ650 sprocket on eBay. These are pretty scarce. Ed


17 Toother

mzandmz wrote:

One place that sells the Stock 16 tooth gear says the 17 tooth was only for racing,

Nope, the 17 up front works very well on the street. Some guys have run the 17 up front AND dropped a couple out back. Great at speed but hell on the clutch taking off in town. You can run the 16/42 all day long on the freeway with no problems but the 17 will relax it a bit with no ill effects around town.

I was running a 15/42 for a few years for the acceleration factor. Pulls a lot harder but 2nd gear comes up real fast and buzzes like crazy on the freeway. It also wears out chain faster due to tighter sprocket circumfrence. I went back to 16/42 and bike runs soooo much better. Next chain, sprocket change I might go to 17 tooth.

I've gone up one tooth on the front sprocket on both the 550 and the 1000. I don't notice any difference in take off, fuel milage or chain wear. I do notice a decrease of between 300 and 500 rpm while cruising in high gear. Just seems like a little nicer ride to me.

I run 17/42 with a 120/90-18 rear tire. My rpm at 70mph is 5000. Works ok in town, most of my riding is commuting, numerous lights and most speeds under 50. Just a tiny bit more of clutch slip, hardly noticeable.