Speedometer Ratio

I did try the search.. didn't find much. So what is the ratio to my 83 KZ550 M1? is it 2240@60? I have the stock wheels, by the way.

Thanks.

Luc

Your bike has the same speedo drive as my bike & I think the tire/wheel sizes are the same.
Speedometers for the 650-CSR have 2240 Rev = 1 Mile printed on the back of them.

The speedometer gear has 26T (41059-026) & the pinion gear has 9T -->> 26/9 = 2.89

My front tire/wheel radius is approx. 13-1/8" = 13.125" = 1.09375'
and using a calculator the circumference is 6.87'
So the wheel spins approx 768 times per mile (5280/6.87=768.3) & the speedo spins 2240revs/mile:
2240/768 = 2.92

martin_csr wrote: Your bike has the same speedo drive as my bike & I think the tire/wheel sizes are the same.
Speedometers for the 650-CSR have 2240 Rev = 1 Mile printed on the back of them.

The speedometer gear has 26T (41059-026) & the pinion gear has 9T -->> 26/9 = 2.89

My front tire/wheel radius is approx. 13-1/8" = 13.125" = 1.09375'
and using a calculator the circumference is 6.87'
So the wheel spins approx 768 times per mile (5280/6.87=768.3) & the speedo spins 2240revs/mile:
2240/768 = 2.92

Thank you, sir! Just what I needed, My former college teacher would see your last paragraph and lose his mind. He hates math. Always uses this... "Train A is traveling at 49 mph. Train B hasn't left the station yet. What color are Rebecca's panties?" Haha.

Thanks again.

I guess I did that right. When looking for an aftermarket speedometer, the type to get should say 2240:60mph or something like that. 2240 is a Japanese thing & indicates the number of revs the speedometer spins in a mile.

The wheel revolutions per mile I calculated is within 1% of 775* (768/775=0.99).
And the ratio I came up with is also within 1% of 2.89 (2.92/2.89=1.01).
775* is probably what Kawasaki uses to do the calculations (2240/2.89 = 775).

The speedo drive gears are probably the simplest way to look at it. The speedo drive receiver couples the wheel directly to the speedo gear, so the gear spins at the same rate as the wheel; with each revolution of that gear, the pinion spins 2.89 times (it has fewer teeth, so it spins faster); using 775 wheel revolutions per mile, the speedometer spins at the rate of 2240 revs per mile. (775 x 2.89 = 2240).