-1 Front sprocket Q's

Very true, it will change the speedo. So I got one of these:
https://www.motomummy.com/store/pro...cat=0&page=1&gclid=CLC5mcHl0q0CFUPd4AodfRdYlw


Works great and cheaper than the speedo healer

For me U$70 is to much expansive just to adjust the speedo!hehe Yes, im stingy!:D:D
But, the speedo sensor isn't in the front sprocket?

Changing the rear one, the front still rotating normally and the sensor will not detect any diference.

I don´t know if my thinking is clear...i hope so!
 
The increased speedometer error is going to cause your MPG readings to be off. If you have a GPS unit on the bike use the odometer on that to compute gas mileage at your next stop and see if it actually changed.
 
I think your right If that is where the speedo sensor is, because by changing the rear sprocket your not changing how many times the front sprocket has to turn but slowing down or speeding up the rpms of the rear wheel, so no healer would be necessary IF big if the sensors is where you said
 
Funny thread . . .
The math says a stock FZ with Stock gears won't redline and certainly won't do a 170mph . .

2nd Gear @ 14,000 RPM:
14,000 * 3.1415 * 24.8
---------------------------------- = 94.3MPH
1056 * 1.9555 * 2.8751 * (G2) 1.947

6th Gear @ 14,000 RPM:
14,000 * 3.1415 * 24.8
---------------------------------- = 169.6MPH
1056 * 1.9555 * 2.8751 * (G6) 1.083

Infor came from thread:
http://www.600riders.com/forum/fz6-...ead-rpm-gear-sprockets-tire-actual-speed.html

Remember; Max HP is @ ~12,000 RPM. Max Tq @~10,000RPM so by 13k I'd imagine a stock bike has given all its gonna give untill you improve the aero. . .
Stock gearing gets us roughly 12,400RPM for ~150mph about 20mph short of the lies above.... :BLAA: nothing personal mind you, but we are not gonna redline this engine in 6th. Other elements like AIR DRAG do play a role. . .

!!!FORMULA!!!!!

RPM * PIE * Tire Diameter (inches)
--------------------------------------------------- = Speed in MPH
1056 * PR * SR * GS

RPM
Primary Reduction Ratio (PR)
Secondary Ratio Front/Rear Sprocket count (SR)
Gear Selection (from manufacture) (GS)
Tire Diameter (from formula) (TD)
1056 (static number in formula)

Yamaha FZ6
Primary Ratio: Engine to Trans (PR): 86/44 = 1.95454
Secondary Ratio: Sprockets (SR): 46/16 = 2.8751

TRANSMISSION RATIOS:
G1 = 37/13 = 2.846
G2 = 37/19 = 1.947
G3 = 28/18 = 1.556
G4 = 32/24 = 1.333
G5 = 25/21 = 1.190
G6 = 26/24 = 1.083

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
I've gone insane. . .

Pick a Ratio and this is what you get. . .

RPM: ____Frt Spr: RearSpr: Ratio = Speed
RPM 13000 - 16 - 46 - Ratio=2.88 = 158.01 (STOCK) 0% change
RPM 13000 - 16 - 47 - Ratio=2.94 = 154.65 = -2%
RPM 13000 - 16 - 48 - Ratio=3.00 = 151.01 = -4%
RPM 13000 - 15 - 46 - Ratio=3.07 = 147.73 = -6%
RPM 13000 - 15 - 47 - Ratio=3.13 = 144.58 = -8%
RPM 13000 - 15 - 48 - Ratio=3.20 = 141.57 = -10%
RPM 13000 - 14 - 46 - Ratio=3.29 = 137.88 = -12%
RPM 13000 - 14 - 47 - Ratio=3.36 = 134.94 = -14%
RPM 13000 - 14 - 48 - Ratio=3.43 = 132.13 = -16%
 
Last edited:
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