Drastic Sprocket Change

[gaillarry]

The stock sprockets on my 85 GS550 is 14/48. I picked up a set of new sprockets and RK chain from the blowout sale at the dealers for $25, 14/43 sprockets and 114 link chain.
Question is how will the smaller rear sprocket affect the bike?

[rapidray]

You will lose some accelleration & gain QUITE a bit on top end MPH if your bike has the power to pull the gearing to redline in high gear. Ray.

[Flying Fish]

You will lose some accelleration & gain QUITE a bit on top end MPH if your bike has the power to pull the gearing to redline in high gear. Ray.

Would you get any improvement in mpg aswell?

[Dave8338]

Would you get any improvement in mpg aswell?

That is a math problem that, will only be known once the bike is back under it's own power. In theory...if there is an excess of HP and or torque, then yes, gearing down (rear sprocket) "should" improve the fuel economy. If, on the other hand...you are running at or near peak performance as the bike is geared now, you may see a drop in the fuel economy. Couple that with slightly more roll on the throttle while slipping through the gears and it could be a wash. Ride it and see! :-D

[80GS1000]

Your revs will be lower across the board for a given speed.

http://www.gearingcommander.com/

You'll lose a lot of grunt...your chain may touch your swingarm too from the decreased diameter of the the rear sprocket...

[Dave8338]

You'll lose a lot of grunt...you chain may touch your swingarm too from the decreased diameter of the the rear sprocket...

And there's a thought that could be "all too true". :shock: Welcome to the world of Cut and Paste. \\/

[80GS1000]

:shock: Welcome to the world of Cut and Paste. \\/

Whaddya mean by that?

[Dave8338]

No Doubt!

Whaddya mean by that?

Your bike...and one I'm working on, RING A BELL!!! :-D :?

[Nessism]

5 teeth less on the rear sprocket will reduce your cruise rpm at normal freeway speeds about 500 rpm. Should be very noticable - good or bad, depending on your point of view.

[Calvin Blackmore]

for your bike @60 MPH stock final drive should make for 5699 RPM 110.5 MPH at 10 500
for the 43-14 combo 5105 RPM @60 MPH 123 MPH at 10 500 RPM

gear calc is fun
sooo you will see a drop in hwy RPMs which will give a reward in gas mileage

I dont recall the HP and torque curves on thsi motor I have a graphic of it somewhere. No matter the bike has gat a lot of power from 5000 rpm up so it should be able to handle this change with ease but it will change your shift points

[focus frenzy]

for your bike @60 MPH stock final drive should make for 5699 RPM 110.5 MPH at 10 500
for the 43-14 combo 5105 RPM @60 MPH 123 MPH at 10 500 RPM

gear calc is fun
sooo you will see a drop in hwy RPMs which will give a reward in gas mileage

I dont recall the HP and torque curves on thsi motor I have a graphic of it somewhere. No matter the bike has gat a lot of power from 5000 rpm up so it should be able to handle this change with ease but it will change your shift points

agreed, the 14/43 combo is a better set up for that bike, I have a road test article on the 83 550es and it was geared for acceleration. in the test it blew right past redline in top gear with ease, clearly indicating it had plenty power to support a smaller sprocket. and it should make a noticeable improvement in economy

[Calvin Blackmore]

oh yes and while i have the L model with this engine I can pull 9500 RPM in top gear at an indicated 118 ish (blurred Needle) MPH so yeah the bike can take taller gearing