Question Lower highway rpms a bit without sacrificing too much acceleration (sprockets)

[Rancid_Ninja]

Hello all I just purchased a new to me 2008 fz6 with 16k miles, dealer put on new tires but chain is still original. Feels to maybe have one or more tight links as it feels a bit off in lower speeds.

Looking at replacing the chain and at the same time doing some sprockets. Noticed the highway rpms were a bit higher than my 04 yzf600r and wanted to bring that down a bit, but not too much.

Using a sprocket calculator I see that the best "middle of the road" sprocket swap would be a +1/+1

Has anyone run this just looking for some input, thanks

 

[Gary in NJ]

Standard sprockets and tire size produce a FDR that turns the engine at 4,954 rpm @ 60 mph in 6th gear.
Going +1 and +1 will yield 4,764 rpm @ 60.

 

[Rancid_Ninja]

Standard sprockets and tire size produce a FDR that turns the engine at 4,954 rpm @ 60 mph in 6th gear.
Going +1 and +1 will yield 4,764 rpm @ 60.

Thank you for the quick reply!

That seems solid, not so much that it's heavily effecting the low/mid range but enough to get the rpms down a bit when I'm cruising at around 70.

Most of my riding is highway speeds around 70.

Maybe I should just do the +1 in the front then I just didn't want it to be too different from stock so I figured adding one in the back would reduce the difference from adding the front one slightly.

Also wondering if stock link count is 118 and that works for the +1+0, if a 120 would work for the +1+1 or just do +1+0 and save the couple bucks on the longer 130 link chain

Edit: Found a calculator that shows 120 links for the +1+1 so I should be good there.

Is there a calculator I can use like the sprocket calc to get those rpm numbers so I can tinker with different numbers without bugging you or how are you getting them?

Thanks again for the reply!

 

[Gary in NJ]

I have a very detailed excel spreadsheet that captures a lot of specs from the FZ6.

Developing a simple spreadsheet you need to know:

6th gear ratio (26/24) @ 1.0833
Secondary Drive Ratio (OEM 46/16) @ 2.875
Final Drive Ratio = (6th Gear Ratio x SDR) @ 6.0876
OEM Tire Size @ 180/55-17 which yields 813.8 revolutions per mile

Formula is (FDR*Wheel Revs)*(MPH/60)

So if you build such a spreadsheet the variables you have are SDR (wheel sprocket / countershaft sprocket) and MPH

 

[Rancid_Ninja]

I found this website called gearing commander .com and it has a ton of info on it, very useful.

I bought the 17/47 setup, hopefully all goes well. I remember last time I did the chain on my yzf600r 3 maybe 4 years ago I had to modify the tool a bit. I gotta check on that and make sure I don't need a new one.

I bought a ek chain and I did see they offer a master link you can screw on and then break the heads off.

Have you heard of those and you think those will hold up?

The chain I purchased comes with a normal rivet style master but I could buy that screw one separately if my tool is no good, probably cheaper than a good tool

Thanks for your help!

 

[Rancid_Ninja]

Sprockets fitted, 120 links for 17/47 is perfect so didn't need to remove any links. I had to go to the store after this for the 30mm socket as I used a 1 1/4 I had to take off the old nut but didn't want to torque down the new nut with the wrong socket.

JT sprockets with ek chain

Website I ordered the chain from said it came with a rivet style master but it arrived with the screw type I had seen separately instead. Followed directions then took Dremel to the remaining threads to smooth out the edges so rags don't get caught on them when cleaning. Haven't ridden it yet waiting for loctite to dry

 

[Rancid_Ninja]

Rode yesterday, feels great. Original chain from 2008 with 16k miles was indeed the lower speeds vibration I was feeling in my pegs.

17/47 with 120 links made it easy to fit new chain, didn't need to remove any links. Negligible rpm change, can recommend.

Rode the yzf600r again after not riding it for a month and wow what a difference! Feels heavier and harder to flick around, and the brakes are definitely lacking compared to the fz