Gear out some (Sprocket Combo Question)

[iviyth0s]

Hey all, so I'm debating to gear out my FZ some since it has so much power and I wanna convert some of that to power to efficiency/fuel economy (and give each gear a little bit more purpose). Back when I owned my Ninja 250 I upped the countershaft sprocket from 14T to 15T to gear it out some and loved the results, didn't notice any power hit but did notice the fuel economy (and obviously it was much better for the bike's longevity not cruising at as high RPMs as before).

My quandary is one that, I'm not sure if I should raise up the CS sprocket or lower the back. (also is there a chart floating around with all the different sprocket combinations and their final drive gear ratios, there was an awesome one on the Ninja forums)

I guess it's easier and cheaper to do the front, but I feel like it makes more sense to shrink the back since you're removing weight in the drive system while also gearing out. A Win-Win. The obvious downside is the new sprocket would likely be tougher to install than just the front would but I feel like it's just more logical to do the back.

Does this make sense?? Is the reason many people bump the CS sprocket up first due to cost/ease of installation or does it have to do with chain length and possibly having to shrink or buy a shorter chain when one down sizes too much with their rear sprocket. (which is still a good thing, weight wise, but an unnecessary pain)

I know it's not the best idea to change just one piece of the drive line trio but I feel like the sooner I gear out, the more I will benefit over the bike's lifespan.

Thanks for the help/input guys!!

 

[Nelly]

Hey all, so I'm debating to gear out my FZ some since it has so much power and I wanna convert some of that to power to efficiency/fuel economy (and give each gear a little bit more purpose). Back when I owned my Ninja 250 I upped the countershaft sprocket from 14T to 15T to gear it out some and loved the results, didn't notice any power hit but did notice the fuel economy (and obviously it was much better for the bike's longevity not cruising at as high RPMs as before).

My quandary is one that, I'm not sure if I should raise up the CS sprocket or lower the back. (also is there a chart floating around with all the different sprocket combinations and their final drive gear ratios, there was an awesome one on the Ninja forums)

I guess it's easier and cheaper to do the front, but I feel like it makes more sense to shrink the back since you're removing weight in the drive system while also gearing out. A Win-Win. The obvious downside is the new sprocket would likely be tougher to install than just the front would but I feel like it's just more logical to do the back.

Does this make sense?? Is the reason many people bump the CS sprocket up first due to cost/ease of installation or does it have to do with chain length and possibly having to shrink or buy a shorter chain when one down sizes too much with their rear sprocket. (which is still a good thing, weight wise, but an unnecessary pain)

I know it's not the best idea to change just one piece of the drive line trio but I feel like the sooner I gear out, the more I will benefit over the bike's lifespan.

Thanks for the help/input guys!!

The front sprocket is usually change as it's cost effective and takes less time.
I have dropped one tooth in the rear sprocket. With improved fuel efficiency and rpm dropped by 1000 rpm when cruising in 6th.
A good few guys have gone up to 17t in the front with no discernible loss of power and improved fuel economy. The 17t also corrects the speedo error.

Neil

 

[ccew]

Hey all, so I'm debating to gear out my FZ some since it has so much power and I wanna convert some of that to power to efficiency/fuel economy (and give each gear a little bit more purpose). Back when I owned my Ninja 250 I upped the countershaft sprocket from 14T to 15T to gear it out some and loved the results, didn't notice any power hit but did notice the fuel economy (and obviously it was much better for the bike's longevity not cruising at as high RPMs as before).

My quandary is one that, I'm not sure if I should raise up the CS sprocket or lower the back. (also is there a chart floating around with all the different sprocket combinations and their final drive gear ratios, there was an awesome one on the Ninja forums)

I guess it's easier and cheaper to do the front, but I feel like it makes more sense to shrink the back since you're removing weight in the drive system while also gearing out. A Win-Win. The obvious downside is the new sprocket would likely be tougher to install than just the front would but I feel like it's just more logical to do the back.

Does this make sense?? Is the reason many people bump the CS sprocket up first due to cost/ease of installation or does it have to do with chain length and possibly having to shrink or buy a shorter chain when one down sizes too much with their rear sprocket. (which is still a good thing, weight wise, but an unnecessary pain)

I know it's not the best idea to change just one piece of the drive line trio but I feel like the sooner I gear out, the more I will benefit over the bike's lifespan.

Thanks for the help/input guys!!

Www.gearingcommmander.com

Useful link.


Sent from my iPhone using Tapatalk - now Free

 

[mave2911]

A good few guys have gone up to 17t in the front with no discernible loss of power and improved fuel economy. The 17t also corrects the speedo error.

Neil

The 17T corrects the speedo error, true - but it also negatively impacts on fuel economy.

I've lost over 2kms per L of fuel (4mi+ to US Gal)

As many predicted, it takes it out of the power range the bike was designed to cruise at. (and worse in town, as it's lost some of it's acceleration - 7%)

Cheers,
Rick

 

[iviyth0s]

The front sprocket is usually change as it's cost effective and takes less time.
I have dropped one tooth in the rear sprocket. With improved fuel efficiency and rpm dropped by 1000 rpm when cruising in 6th.
A good few guys have gone up to 17t in the front with no discernible loss of power and improved fuel economy. The 17t also corrects the speedo error.

Neil

Really, 1000rpms?!

Yeah, I'm pretty interested in correcting the speedo error...Since my car is spot on GPS accurate, it's painstakingly obvious that my FZ is slower than what it's saying. Would this also make the odometer accurate too?? (and therefore, my fuel economy calculations more accurate)

Www.gearingcommmander.com

Useful link.


Sent from my iPhone using Tapatalk - now Free

Thanks! That is too neat, I'm gonna nerd over there for a bit and play around with the combinations!

The 17T corrects the speedo error, true - but it also negatively impacts on fuel economy.

I've lost over 2kms per L of fuel (4mi+ to US Gal)

As many predicted, it takes it out of the power range the bike was designed to cruise at. (and worse in town, as it's lost some of it's acceleration - 7%)

Cheers,
Rick

If I'm correct, it negatively impacts your *perceived* fuel economy in that it's showing you the true speed/mileage your going instead of an overly optimistic rating which would give the illusion that you're losing fuel economy or simply, that your fuel economy did not improve.

I would think as long as you're not bogging down, it should always deliver better fuel economy with lower revs since it's not like it's carbureted and the carburetor will just dump in the fuel like a moron. I would think the computer would tell the injectors to inject less fuel since less is needed to maintain that particular amount of RPMs. (referring to the cruise situation, not the slight acceleration lag in city riding)

 

[fb40dash5]

If I'm correct, it negatively impacts your *perceived* fuel economy in that it's showing you the true speed/mileage your going instead of an overly optimistic rating which would give the illusion that you're losing fuel economy or simply, that your fuel economy did not improve.

I would think as long as you're not bogging down, it should always deliver better fuel economy with lower revs since it's not like it's carbureted and the carburetor will just dump in the fuel like a moron. I would think the computer would tell the injectors to inject less fuel since less is needed to maintain that particular amount of RPMs. (referring to the cruise situation, not the slight acceleration lag in city riding)

This. If the speedo is 10% optimistic (which is the number I've heard tossed around) then correcting it will reduce your *calculated* mileage by that same amount. Youre using the same fuel (or close anyway) to go the same 100 miles... just that 100 miles is now really 100 miles, not 91 miles. I also noticed a mileage drop when I regeared, used to be able to get about 50, now its more like 42-45... but I'm also a bit more throttle-happy than I used to be.

 

[mave2911]

Really, 1000rpms?!

Would this also make the odometer accurate too?? (and therefore, my fuel economy calculations more accurate)

No, there is one signal wire, so whatever you change the speedo by, will directly change the odometer by the same margin.

If I'm correct, it negatively impacts your *perceived* fuel economy in that it's showing you the true speed/mileage your going instead of an overly optimistic rating which would give the illusion that you're losing fuel economy or simply, that your fuel economy did not improve.

No perception about it - I have logged every single kilometer (over 22000) I have ridden on the Fizzer (bar the first two tanks) - I adjust the reported mileage by the known margin. (check sig)

I would think as long as you're not bogging down, it should always deliver better fuel economy with lower revs since it's not like it's carbureted and the carburetor will just dump in the fuel like a moron. I would think the computer would tell the injectors to inject less fuel since less is needed to maintain that particular amount of RPMs. (referring to the cruise situation, not the slight acceleration lag in city riding)

Strangely enough, so did I (despite the popular opinion is would negatively impact mileage) and it has dropped my economy by more than 2k/L (4+mi/USgal)

Cheers,
Rick

 

[Nelly]

No, there is one signal wire, so whatever you change the speedo by, will directly change the odometer by the same margin.



No perception about it - I have logged every single kilometer (over 22000) I have ridden on the Fizzer (bar the first two tanks) - I adjust the reported mileage by the known margin. (check sig)



Strangely enough, so did I (despite the popular opinion is would negatively impact mileage) and it has dropped my economy by more than 2k/L (4+mi/USgal)

Cheers,
Rick

Are you still riding in the same gears at the same speed? Reduced economy could be down to the engine bogging down. Or is it a question of having to stay in the lower gears now to have useable power on your commute which has increased your fuel useage.
My commute is about 20% town and the rest is good fast roads.

Nelly

 

[outasight20]

I've had the 17T front sprocket installed for most of the time I've owned my bike. I love it. My best tank of fuel returned 58 MPG. And I still ran a 11.7 second quarter mile

 

[iviyth0s]

I've had the 17T front sprocket installed for most of the time I've owned my bike. I love it. My best tank of fuel returned 58 MPG. And I still ran a 11.7 second quarter mile

Damn! I've been getting like 47MPG and I have been riding it pretty conservative.

What's you get with the 16 up front??

 

[outasight20]

The difference between the 16T and 17T as far as mileage is concerned was about 5%. That 58 MPG tank was all back roads at a constant 40-55 MPH.

 

[iviyth0s]

The difference between the 16T and 17T as far as mileage is concerned was about 5%. That 58 MPG tank was all back roads at a constant 40-55 MPH.

Oh, the truth comes out! lol

I guess my mileage would be worse doing like 80-90 on the way to school most of my tanks

 

[FinalImpact]

The old school way is to connect a vacuum gauge to it and determine the load imposed based upon the vacuum drop. i.e. as you climb hills the torque required to maintain the same speed increases and the vacuum drops. This can also happen from gearing up. As mentioned above, if you have to "open the throttle more" to maintain the same speed, you lost ground. You may actually get better mpgs by dropping the front count and spinning the engine more as its doing less work.

Gear it up as you wish and check the vacuum, if its the same you may improve your MPGs. If it drops, so will your MPG.

I did this for "other reasons" as I anything over 40 is fine by me.

If someone were to burn a couple tanks down on fixed route doing the same speed and rates of acceleration, it would be interesting to see. Style matters! Good luck what ever you do!

 

[iviyth0s]

The old school way is to connect a vacuum gauge to it and determine the load imposed based upon the vacuum drop. i.e. as you climb hills the torque required to maintain the same speed increases and the vacuum drops. This can also happen from gearing up. As mentioned above, if you have to "open the throttle more" to maintain the same speed, you lost ground. You may actually get better mpgs by dropping the front count and spinning the engine more as its doing less work.

Gear it up as you wish and check the vacuum, if its the same you may improve your MPGs. If it drops, so will your MPG.

I did this for "other reasons" as I anything over 40 is fine by me.
PICTURE!

If someone were to burn a couple tanks down on fixed route doing the same speed and rates of acceleration, it would be interesting to see. Style matters! Good luck what ever you do!

That's a pretty nice setup/idea, I would love to be the guinea pig in that if there was someone who is running a smaller rear or larger front sprocket that would also run the same assessment at the same speeds and gears.

Where do you connect the pressure line to, the airbox?

 

[FinalImpact]

That's a pretty nice setup/idea, I would love to be the guinea pig in that if there was someone who is running a smaller rear or larger front sprocket that would also run the same assessment at the same speeds and gears.

Where do you connect the pressure line to, the airbox?

There's a pressure sensor under the tank. Place a "T" in that line. Its the easiest access IMO. FYI: it has 3 wires and hose going to it.

Go for it!
That was a one time deal for about 12 miles just to get some ball park figures of how much vacuum can it pull during quick deceleration.

 

[iviyth0s]

There's a pressure sensor under the tank. Place a "T" in that line. Its the easiest access IMO. FYI: it has 3 wires and hose going to it.

Go for it!
That was a one time deal for about 12 miles just to get some ball park figures of how much vacuum can it pull during quick deceleration.

I see, did you have the hose, gauge and mount all sitting around or is there a kit for that (I'm lazy) lol

 

[FinalImpact]

Negative. Just stuff from wrenching over the years. A good gauge should do the trick. Then grab some hose and a matching T and find a way to mount it.

 

[iviyth0s]

Negative. Just stuff from wrenching over the years. A good gauge should do the trick. Then grab some hose and a matching T and find a way to mount it.

Gotcha, I'll have to look into it. It's sort of like a rudimentary MPG indicator