Gas Mileage And Sprocket Teeth

[David Allaband]

Hi all. I'm thinking of doing some very long highway miles and a friend (not an FJ guy but an old cyclist) recommended switching out both sprockets to get lower RPMs on the interstate and therefore better gas mileage.

Has anyone experimented with this? What kind of gas mileage do you get with different sprockets? Will I need a new chain? Is there any advantage at all?

Seems to me if I ride from NYC to LA and Back the gas saved might not even pay for the new parts.

Any thoughts?

Thanks!

[FJmonkey]

I am running 18 front, 38 rear and getting 46to 48 MPG... And that is with SupperTrapp slip-on pipes, UNI pods and the jetting. NOT TOO BAD EH? 

[aviationfred]

Dave,

I am running a 18t front and a 38t rear. When I rode to Colorado in July, When I was doing highway riding I got 53mpg.

Mathematically that is 307 miles to a tank.  

I did put a new chain on when I did the swap. I got a 110 link chain and removed one link.

Fred

[Bminder]

I am running 18 front, 38 rear and getting 46to 48 MPG... And that is with SupperTrapp slip-on pipes, UNI pods and the jetting. NOT TOO BAD EH? 

So what's low speed acceleration and starting out like? I mean like when you're driving at low speeds in town.

[Bminder]

Dave,

I am running a 18t front and a 38t rear. When I rode to Colorado in July, When I was doing highway riding I got 53mpg.

Mathematically that is 307 miles to a tank.  

I did put a new chain on when I did the swap. I got a 110 link chain and removed one link.

Fred

So what's low speed acceleration and starting out like? I mean like when you're driving at low speeds in town.

[Capn Ron]

I have never changed the gearing on my motorcycle, but have some thoughts on this. 

I have a car that gets 70MPG on long trips and often think about mileage and how I can improve it.  Mostly as a way of keeping my mind occupied on said long trips.   

*  You'll notice a far greater fuel mileage increase just by changing your throttle, shifting, coasting and braking habits.
*  Changing to a taller gearset will force a change in the above habits, likely to the detriment of fuel mileage.
*  As it stands, you can cruise along all day in 5th gear.  With a taller setup, you may find yourself downshifting more often.
*  I rode LA to Nova Scotia and back (17,286 miles) with Givi hardcases (extra 120 lbs + wind drag) and averaged 46MPG with stock gearing.
*  Let's dream you could up the mileage by 5MPG and get 51MPG???  In a 6000 mile trip from NYC to LA and back, you'd save $48 in fuel.
*  If fuel mileage was your *only* goal in a specific driving window (freeways), it might be worth doing, but you'll likely negatively effect drivability as well as fuel mileage in the real world.

Cap'n Ron. . .

[FJscott]

Good points capt

[markmartin]

I went from stock to 18/38 this spring.  As far as I can tell, I get the same MPG now as before the change.  I find the way I drive and a good carb sync has more effect on mpg than the gearing does.  

I get the best gas milage (45+mpg) when riding 2-up and loaded, following the speed limit, accelerating moderately, and slowing down well ahead of the next stop sign.  

[markmartin]

So what's low speed acceleration and starting out like? I mean like when you're driving at low speeds in town.

  It makes for a taller 1st gear which I like especially when turning onto streets.  Probably a tad more clutch is needed when starting but it isn't a problem.

[Harvy]

I went from stock to 18/38 this spring.  As far as I can tell, I get the same MPG now as before the change.  I find the way I drive and a good carb sync has more effect on mpg than the gearing does.  

I get the best gas milage (45+mpg) when riding 2-up and loaded, following the speed limit, accelerating moderately, and slowing down well ahead of the next stop sign.  

Could not have said it better myself.
I've been on 18/38 since the Yahoo group days (around 100,000 Kms now). Still on the original clutch with no slip encountered so far. The bike does not accelerate has hard (obviously) but on 5000Km trips makes for more relaxed cruising in the 100 - 120 KPH range (ie hovering around the 4000rpm area). In 5th the torque there is perfect for passing without having to change down and I am still motoring (not pushing) with fuel to spare at 350kms.
I think if you are more of a canyon blaster maybe its too much gearing, but for me its just about perfect.

Horses for Courses.
Harvy

[ribbert]

The gearing range most are using ( 17/18 - 38/41) isn't going to have much effect on economy, if any. It is more about the bike feeling relaxed at highway speeds with slightly lower revs. You will notice a bigger change in acceleration than you will in fuel consumption.

There are many, many things on the bike that will effect fuel economy more than gearing.

I have tried an few combinations over 2 bikes and settled on 18/41, it suits me, but I also avoid roads with constant cruising speed like the plague and would not want to trade off any more acceleration.

The FJ is for fun and it would a crime to nobble any part of that to save a few bucks at the bowser. Skip one coffee stop while on a ride and you have just saved more money than any gearing change will save you on fuel.

Someone here once said "Riding an FJ for economy is like going to a prostitute for a hug"

I agree.

Noel

[Capn Ron]

"Riding an FJ for economy is like going to a prostitute for a hug"

Noel

But some of them are REALLY good huggers!   

Cap'n Ron. . .

[Bminder]

"Riding an FJ for economy is like going to a prostitute for a hug"

Noel

But some of them are REALLY good huggers!   

Cap'n Ron. . .

Aside from the morals of it, the thing I don't get about it is why would any man... well to paraphrase name T. Kirk, boldly go where hundreds of men have gone before.

[ribbert]

"Riding an FJ for economy is like going to a prostitute for a hug"

Noel

But some of them are REALLY good huggers!   

Cap'n Ron. . .

Aside from the morals of it, the thing I don't get about it is why would any man... well to paraphrase name T. Kirk, boldly go where hundreds of men have gone before.

Hmmm, given the humour translation fails lately, I'll leave that one alone.

[AustinFJ]

"Riding an FJ for economy is like going to a prostitute for a hug"

Noel

But some of them are REALLY good huggers!   

Cap'n Ron. . .

Is that what Ron White called a "mouth hug"?