Gear ratios

[ang1dust]

So i did some homework and found that the FZ6 (2007) is geared as follows.
15 tooth front sprocket
46 tooth rear sprocket
1.955 Primary drive ratio

1st gear 2.846
2nd gear 1.947
3rd gear 1.556
4th gear 1.333 (repeating)
5th gear 1.19
6th gear 1.083

I found a motorcycle gearing worksheet online to enter my values but even that didnt line up with my current speed / rpms.

So i took it into my own hands and decided to increase the front gear (as you would on your bicycle) in order to increase my MPG beacuse the primary use of my bike is getting to work (130mile commute a day). I havent put it on yet because i lack the appropriate tools. It doesnt seem hard but i want to make sure im doing this right.

I went with a 17 tooth front sprocket. All i need to do is remove the bolt, slide the old one off, slide the new one on (add the chain tension), and tighten the bolt?

The spreadsheet i used to calculate the speed of the bike was off by roughly 8mph in most places over 3rd gear. However when i input the 17 tooth it jumps the Max speed from 160 at 14,000 rpms to 181 at 14,000 rpms. Is it just me or is that a big jump? Ill report the gas mileage once i get it on in the thread for gas mileage *duh*

Oh btw, can i get a pol or idea on what companies are best to buy from for the Chain / Sprockets / Website to buy from?

[Nelly]

Hi mate,
I have changed front spockets on various bikes in the past. Ratio's and technical stuff like that means very little to me. From a practical point of view. You have got it pretty much right on how to change it. You will need to come up with a way to stop the back wheel moving to undo the locking nut. Previously I have just used the back brake. I'm not sure if this will work with the FZ6. As for the MPH increase this is thoeoretical, the engine may not be able to pull 14000 in top with the altered gearing. on another note , Is the standard chain long enough to take the bigger sprocket, and allow for th2 55mm free play? I don't know? good luck, let us know how you get on.

[JONAC]

Neil have you changed your Fz6 gearing ??

[Nelly]

Originally Posted by JONAC

Neil have you changed your Fz6 gearing ??

No Mate,

I'm still to busy changing nappies at the mo lol, Im gona start fiddling next year when the babies are a bit bigger.

[DanG]

Is the speedo driven by the output of the gearbox, because I don't see any speedo drive/cable on the front wheel? This'd mean that changing your gearing will make the speedo reading inaccurate?

[pedwards89]

Originally Posted by DanG

Is the speedo driven by the output of the gearbox, because I don't see any speedo drive/cable on the front wheel? This'd mean that changing your gearing will make the speedo reading inaccurate?

Yep, the speedo is electronic. So, apparently what you need is a speedo healer, to correct the deviation. Alternatively, work out the milestones by going with the flow of traffic & leave the rest to luck.

Nothing has chained since 2004 it remains as follows:

Transmission Constant mesh, 6-speed
Final transmission Chain
Primary reduction ratio 86/44 1.955
Secondary reduction ratio 46/16 2.875
Gear ratio:
Gear ratio-1st gear 37/13 2.846
Gear ratio-2nd gear 37/19 1.947
Gear ratio-3rd gear 28/18 1.556
Gear ratio-4th gear 32/24 1.333
Gear ratio-5th gear 25/21 1.190
Gear ratio-6th gear 26/24 1.083

I found the original post odd as the FZ6 has always had a final drive of 16/46 where the R6 used the 15.

[opds9091]

i have a question. I am getting ready to buy a sprocket kit that comes with
-520 RX in RED
-front sprocket 15teeth
-rear 48/49 all for $130 all new from ebay, does anyone forsee problems. I know i will lose top end and the speedometer will be a little off. Any other problems?????????

Originally Posted by opds9091

i have a question. I am getting ready to buy a sprocket kit that comes with
-520 RX in RED
-front sprocket 15teeth
-rear 48/49 all for $130 all new from ebay, does anyone foresee problems. I know i will lose top end and the speedometer will be a little off. Any other problems?????????

At 16/46, the standard set up, you are at 2.875:1 At 15/48 you will be at 3.2:1
If you dropped the standard set up to 15/46 you would be at 3.06:1 and with this the bike flat comes alive across the board from low to high. You are correct in that you WILL need a speedohealer as it will be about 20mph off at speed. With the 15T mine was off 15mph happy at 70mph. At 3.2:1 that bike will scream and your fuel range will drop way off too....

[2X80MPH]

Give this site a try... I think you will find it helpful!

Gearing Commander: Motorcycle Gearing Ratio Sprocket RPM Speed Chain Calculator

"The bitterness of poor quality remains long after
the sweetness of a cheap price is forgotten!"