I am toying with the idea of changing the rear sprocket

[MIJ_FZ6]

Goals are simple. A bit of extra umph in the lower RPMS, not a wheelie machine (not yet at least . I do not ride on the highway and rarely go over 80 mph. Thankfully this bike gets out of first around 55mph, but even then I find myself climbing up those RPMs to get that power on the street. I've been doing some reading on replacing the sprocket and just like my oil thread a bit ago, I know the information already exists if I search, just want to get some new data.

In this video, the guy explains he is just doing a tad bit bigger +2 sprocket in the rear and nothing in the front. Looks like a new chain will not be needed which makes it an easy mod to do.

https://youtu.be/08N1M3LKokM?t=64

- How big of a difference is this? I doesnt sound like it will be a power wheelie machine unless you replace the front sprocket as well.
- How off will my spedo be?

Sprocket he used: https://www.amazon.com/gp/product/B0068ETN2S/

Any suggestions are appreciated, as well as a sprocket brand/retailer.

 

[FB400]

Going down 1 tooth in the front will net you the same gain as going up 2 in the back. Some people do both but that might require a longer chain - not sure. I was plenty happy enough with the 15T up front (1 down). I never considered changing the rear sprocket.

For speedo you will need a calibrator. I use SpeedoDRD and it works great. Easy plug and play installation.
SpeedoDRD

 

[MIJ_FZ6]

Going down 1 tooth in the front will net you the same gain as going up 2 in the back. Some people do both but that might require a longer chain - not sure. I was plenty happy enough with the 15T up front (1 down). I never considered changing the rear sprocket.

For speedo you will need a calibrator. I use SpeedoDRD and it works great. Easy plug and play installation.
SpeedoDRD

Sweet! Looks nice, not too expensive either. I soppose the rear sprocket is OEM and healthy, no real prefrence to change either. Front might be easier to replace too. Can you recommend a sprocket to go with (actual link to a product)?

First time doing this, but by correcting your spedo, you are also correct the mileage counter right?

Thanks!

 

[FB400]

I am presuming you have the stock chain? You need to match the chain with the sprocket. the stock chain is 530 weight and that means you need a 530 sprocket. be careful not to use a 520 sprocket as it would be too light for the stock chain.

The front sprockets are a somewhat product - it need not be expensive to work.
I used this one - pretty inexpensive and works great with no issues
https://www.ebay.com/itm/JT-530-15T...h=item1ecfd2ab54:g:ek0AAOSwq9NZwuK3:rk:2:pf:0

I am not really sure if correcting the speedo display also corrects the ODO rate. I would make a presumption that it does. I cannot imagine a separate mechanism to keep track of miles.

Good luck.
This is a pretty easy Mod. I would give it a rating of 4/10 for difficulty. The hardest part is getting the nut off. Come back to us with questions.

 

[TownsendsFJR1300]

There shouldn't be any problem with your plus 2 in the rear.

As the guy in the video stated, he used the stock chain, NO NEED for a longer chain. The Vortex STEEL sprocket should be fine.


He stated (I cannot verify), that the +2 in the rear, compared to -1 ONLY in the front, is about 2/3's the difference, not quite such a difference.. The larger sprocket in the rear vs a smaller in the front is also EASIER on the chain-NOT so tight a bend.

As for the speedometer, ANY change (even with the stock gearing, the speedometer is OFF-reading high).

I have the stock gearing on mine and use a "Speedohealer" to get the speedometer within .2 MPH with my GPS.
It's plug and play, NO cutting of wires. It also has a "TSM" Top Speed Memory (you can or don't have to plug in) a thing that records your TOP SPEED by and displays it with the push of a button thru the speedometer..

Any speed "adjusting device" you use, you should calibrate with a GPS.


https://www.healtech-electronics.com/products/sh/

 

[Gary in NJ]

Let's answer the question with good old fashioned math.

The stock final drive gearing 16F : 46R yielding a final drive ratio of 6.0876 in 6th gear. There's your baseline.

15:46 produces an FDR of 6.4934, a change of 6%
16:48 produces an FDR of 6.3523, a change of 4%
16:49 produces an FDR of 6.4846, a change of 6%

So if you want the result of dropping the front by one tooth, than you'd have to increase the rear sprocket by 3 teeth.

Other info:

16:46 results in 4,954 rpm @ 60 mph
15:46 results in 5,284 rpm @ 60 mph
16:48 results in 5,169 rpm @ 60 mph

Last bit of info...

With the stock gearing you can acheive 60 mph in 1st gear
With 16:48 you'll only get to 58 mph in 1st gear, but you'll get there quicker

 

[MIJ_FZ6]

Let's answer the question with good old fashioned math.

The stock final drive gearing 16F : 46R yielding a final drive ratio of 6.0876 in 6th gear. There's your baseline.

15:46 produces an FDR of 6.4934, a change of 6%
16:48 produces an FDR of 6.3523, a change of 4%
16:49 produces an FDR of 6.4846, a change of 6%

So if you want the result of dropping the front by one tooth, than you'd have to increase the rear sprocket by 3 teeth.

Other info:

16:46 results in 4,954 rpm @ 60 mph
15:46 results in 5,284 rpm @ 60 mph
16:48 results in 5,169 rpm @ 60 mph

Last bit of info...

With the stock gearing you can acheive 60 mph in 1st gear
With 16:48 you'll only get to 58 mph in 1st gear, but you'll get there quicker

SOLD! hehe

Thanks everyone for the info! I think I want to try the 15t front sprocket due to it being a bit cheaper/easier. For a 2009, is it as simple as this person states to remove the nut over the front sprocket? https://youtu.be/5BYq-dHYCg4?t=146

 

[TownsendsFJR1300]

Thanks everyone for the info! I think I want to try the 15t front sprocket due to it being a bit cheaper/easier. For a 2009, is it as simple as this person states to remove the nut over the front sprocket? https://youtu.be/5BYq-dHYCg4?t=146

Basically yes...

But, I would NOT stick it in gear. I put a padded (keep from scratching) steel rod / tube thru the rear wheel, up against the swing arm (with the chain on and still adjusted. Then loosen / tighten with your socket. The chain/bar takes all the 61 lbs /ft torque your applying to it, not the gear box..

And don't kick wrenches, shessh… He had a breaker bar and a tube that could go over it for more leverage...

If doing the rear sprocket too, break those loose (and fully tighten) while the chain is still on, just like the front sprocket..

 

[Smittyboy]

Basically yes...

But, I would NOT stick it in gear. I put a padded (keep from scratching) steel rod / tube thru the rear wheel, up against the swing arm (with the chain on and still adjusted. Then loosen / tighten with your socket. The chain/bar takes all the 87 lbs /ft torque your applying to it, not the gear box..

And don't kick wrenches, shessh… He had a breaker bar and a tube that could go over it for more leverage...

If doing the rear sprocket too, break those loose (and fully tighten) while the chain is still on, just like the front sprocket..

100% agree! Don't rely on the trans to absorb all of that when it doesn't have to. I had a friend basically stand on the rear brake (bike in N) and it was enough to break it free.

 

[FB400]

I think the torque spec is 65 ft lbs. It will feel a little tough cracking the nut for the first time. As Scott has advised using a dimensional piece of wood through the spokes of the wheel against the swingarm will give you the stop that you need. I usually stomp hard on the rear brake as well while sitting on the bike and working the 1/2 cracker bar to loosen the nut. After you do this once you will see it is not that bad. For awhile there I was swapping the front sprocket several times to find one I liked more. Good luck

 

[TownsendsFJR1300]

Correction, the front sprocket nut (per the Yamaha manual) is 61 lbs /ft, NOT 87.

Brain fart on my end, 87 is the rear axle.

As noted, you can use the rear brake, in neutral, but W/O a helper, kinda odd position and I would not want to bugger up that nut...

I tried some fairly heavy wood the first time (padded) and snapped that easily.

If you have an air gun, you can spin that nut off W/O blocking anything. You'll still need to secure the wheel when re-installing / torqueing the nut. Don't forget to flatten the nuts outer edge.

NOTE: *Yamaha DOES CALL FOR REPLACING that NUT*..

 

[MIJ_FZ6]

Thanks again for the great info - Glad I do not need to leave it in gear

Correction, the front sprocket nut (per the Yamaha manual) is 61 lbs /ft, NOT 87.

Brain fart on my end, 87 is the rear axle.

As noted, you can use the rear brake, in neutral, but W/O a helper, kinda odd position and I would not want to bugger up that nut...

I tried some fairly heavy wood the first time (padded) and snapped that easily.

If you have an air gun, you can spin that nut off W/O blocking anything. You'll still need to secure the wheel when re-installing / torqueing the nut. Don't forget to flatten the nuts outer edge.

NOTE: *Yamaha DOES CALL FOR REPLACING that NUT*..

Good call, I looked up the nut. Part = 90179-20010-00 and the washer that goes behind it is 90201-20023-00

Im going to use my best judgment here, if it looks healthy I may not replace it but keep an eye on it. It's only a 10 part. Picked up the 15t sprocket today, will install it in the next few weeks. As always, I am going to double check the torque values in the manual.

 

[TownsendsFJR1300]

My old nut looks like new.

I suspect Yamaha wants it changed out "just in case". Like when you bend metal back and forth a lot, it'll break.

The thin part tapped down into the output shaft really doesn't get mashed back and forth. As it comes off, the indentation
comes back out and the sprocket looks as new..

 

[FB400]

The Nut keeping the sprocket in place is pretty durable. I have re-used it several times. the retaining washer I replaced though after about 4 iterations of sprocket changes

 

[FinalImpact]

16/48 here using an OEM Sunstar. There is not enough chain to go 16/49. Look down here....

Thread looks pretty useless with all the attachments gone. lol Home Brewed Bazzaz Z-AFM Map at 13.0 AFR above 5% TPS is pretty good. Sounds good, pulls great, seems very happy!

Audio track after getting it dialed... MP3 from Soundcloud - playing in the canyon
Around the 4:00" mark speed is 25mph in 3rd, drop to 2nd and opened it up!

Link to 48T sprocket : Transformation Complete! It's All BLACK!



Sunstar 2-547448+48
Sunstar 48 teeth

Top Down FZ1 Bar pic:

Columbia river bar... View from Astoria