83GS550E Sprocket Size For Increased Speed/Lower RPM?

[GQROD]

I was counting the teeth at the top of the links. While rotating the wheel in neautral.

I used this link below to a calculator and the numbers for a 14-48 are almost exaclty what i'm seeing it's off by about 10 mph.

I entered all the ratios taken from the factory manual.

Which means i'd have to run the RPM's to almost 8000 to be at 65 MPH ????????? YIKES !

I'm definelty going to have to find a better combination. I don't think one tooth size up alone on the front sprocket is going to cover it.

http://www.gearingcommander.com/ - 2k

I'd like to do 65 mph in 6th gear at 4000 to 5000 RPM max am i deluding myself in thinking this is practical????

[GQROD]

Did more reasearch by using the search feature here and found great info.

From what i got using the calculator i got two sets of numbers

16/44 gets me in the ball park.

18/35 Being ideal ratio to do 65-70 mph in the 4000-5000 RPM range.

or just go with a 18 tooth front sprocket ( this reduces according to the +1 front = -3 rear formula to 18/35 )-providing i don't have clearance issues etc.

I know about the 16 valves not having gobs of torque, don't mind downshifting to pass and i don't intend on doing more than 80 on the highway. So i can live with sacrificing roll on power to shift less and have a less buzzy vibration free ride.

I'm not a math wiz so feel free to chime in with advice it is appreciated.

[p_s]

I wouldn't trust the numbers you get from 25 year old analog gauges. Trust the numbers from the back page of this:

http://junkyman.org/gs550es/Cycle_World_83.pdf

or this:

http://junkyman.org/gs550es/cycle_83_review.pdf

and you'll see you don't need such a drastic change to get to 5k at 65 mph.

And if you up the gearing by 10% you'll have to shift more, not less, to make power.

[Old Colt]

The original front was a 14T, If it had a 13, Rare, that would be a big difference.
I expect many of us will recommend getting 15 or 16 for the front. I would say just get a 16 tooth and run that.
This way you do not need to change the chain or anything else.

[Calvin Blackmore]

Did more reasearch by using the search feature here and found great info.

From what i got using the calculator i got two sets of numbers

16/44 gets me in the ball park.

18/35 Being ideal ratio to do 65-70 mph in the 4000-5000 RPM range.

or just go with a 18 tooth front sprocket ( this reduces according to the +1 front = -3 rear formula to 18/35 )-providing i don't have clearance issues etc.

I know about the 16 valves not having gobs of torque, don't mind downshifting to pass and i don't intend on doing more than 80 on the highway. So i can live with sacrificing roll on power to shift less and have a less buzzy vibration free ride.

I'm not a math wiz so feel free to chime in with advice it is appreciated.

47-14 is about 7000 at 70 maybe im wrong

[GQROD]

I wouldn't trust the numbers you get from 25 year old analog gauges. Trust the numbers from the back page of this:

http://junkyman.org/gs550es/Cycle_World_83.pdf

or this:

http://junkyman.org/gs550es/cycle_83_review.pdf

and you'll see you don't need such a drastic change to get to 5k at 65 mph.

And if you up the gearing by 10% you'll have to shift more, not less, to make power.

You are right i will have to downshift more but i don't mind and thanks for the links they were a lot of help. And finally makes sense of this.

Thank you all again for your help. I think it makes sense as you have suggested to go with a 16 and test it. I can always go higher if this is not enough.

Old colt and calvin thanks for your suggestions,

I wonder though would i have to add links to the chain?? to make it longer to keep it in the slots for adjustibilty?

[Old Colt]

Not with changing just the front.

[Commodus]

Um. Earlier in the thread you were saying something about really bad fuel mileage, no? I think you should fix the bike before modifying it. Find this problem and deal with it and then you may find there's no need to play with gearing.

[GQROD]

Um. Earlier in the thread you were saying something about really bad fuel mileage, no? I think you should fix the bike before modifying it. Find this problem and deal with it and then you may find there's no need to play with gearing.

I have already cleaned the carbs, and tuned it. The main jets are stock, the pilots are one size up from 35 to 37.5 and the valves were adjusted.Plugs are new. Electrical is all new.

I'm not sure what else could be cuaseing such high consumption and the gearing is driving me nuts.

[GQROD]

Not with changing just the front.

Sweet, thanks old colt i will definetly order the front gear and try it. Are these available through z1 enterprises or is there another vendor i should try?

[Old Colt]

Yes, and most all the Suzukis have the same spline so there is a vast amount of interchange for these sprockets. You just need it for a 530 chain size for a Suzuki. Very common part.

[GQROD]

Yes, and most all the Suzukis have the same spline so there is a vast amount of interchange for these sprockets. You just need it for a 530 chain size for a Suzuki. Very common part.

Thank you very much i can't tell you how much i appreciate the advice and help. I'll order it and see how it goes and update this thread.

[Commodus]

I recommend:

1) Verify the information you're getting by verifying the accuracy of the gauges.

2) Calculate your fuel mileage accurately.

With this information, you will be able to at least tell if you're going down the right path. Right now you're just shooting in the dark, trying to hit your problem. You can't know if the 'excess' revs are a problem if you don't know if the bike is running properly, and especially if you have an indication that something is amiss. It could very well be that if you find something, the bike will be smoother at 8K rpm than it is now at 3K rpm.

That's just my .02.

[Calvin Blackmore]

I have already cleaned the carbs, and tuned it. The main jets are stock, the pilots are one size up from 35 to 37.5 and the valves were adjusted.Plugs are new. Electrical is all new.

I'm not sure what else could be cuaseing such high consumption and the gearing is driving me nuts.

so what is your average consumtion
unfaired twin gets 50 mpg to an imperial gallon at moderate speeds below 60 MPH
drops off if you are revving high but 70 mph in top gear will net just over 100 miles on 2.5 gallons

as for the jets us specs were lean my cnadian carbs have the same jets as you.

[GQROD]

I recommend:

1) Verify the information you're getting by verifying the accuracy of the gauges.

2) Calculate your fuel mileage accurately.

With this information, you will be able to at least tell if you're going down the right path. Right now you're just shooting in the dark, trying to hit your problem. You can't know if the 'excess' revs are a problem if you don't know if the bike is running properly, and especially if you have an indication that something is amiss. It could very well be that if you find something, the bike will be smoother at 8K rpm than it is now at 3K rpm.

That's just my .02.

Makes a lot of sense, The gearing is more for my peace of mind and comfort at cruising speed. I'm not thrilled about winding out a 25 year old engine to 8000 RPM and have something come loose.

The gas miles is what i noticed as odd since the bike is tuned (carbs, electrical ) i wasn't sure where to look next.

Other than the noise at 3000 to 4000 RPM being odd, which can only mean vac sync is needed again ( just did it a couple of months ago ) or it has a bent rod? i only hear it under load.