Larger Countershaft Sprocket?

[Elmojo]

Hi All,

I checked out Ronayers.com and Sprocket Specialists last night, and found that I can get a slightly larger front sprocket AND a new gasket for around $35.00, shipping included.  Of course, I only pay shipping for the sprocket, since Ron Ayers is about 3 miles from here.  

Do you think I'll see a significant (200-300) RPM drop in top gear from the larger gear up front or am I wasting my time?
This bike has more power than I need, and I'd love to get a bit better mileage.  Right now I'm only getting about 37mpg mixed hwy/city on Regular Unleaded.
Would the 16 tooth be enough or should I go to a 17?

Thanks,

Mike P.

[B12Teuton]

What gasket??

A 1 tooth jump in the front is = to about 3 in the rear.  This will make a noticeable difference, and for the $$, you can't go wrong.
If you have a second generation B12, your speedometer is driven off the countershaft, so a sprocket change will affect the accuracy of the speedo.  In this case, it may actually correct the built-in speed error and make it read the right speed.

Check also www.vortexracing.come for sprockets.

[Red01]

A 16T sprocket will change your gearing from stock 3:1 to 2.81:1, or about a 7% change, so you can expect a 7% drop in rpm, or ~280 rpm at 70 mph.

A 16T sprocket requires slight trimming inside the countershaft cover on most, but not all, B6's & B12's. This means a 17T will not fit. If you want to further reduce rpm, you'll need to drop teeth from the rear sprocket.

[99er]

I guess it depends upon where and how you ride. I figured I had plenty of power and mounted a 16 tooth. Minor mod to the cover was required for chain clearance. It was fine until I hit the road. On GA400 to the mountains, I was right at the vibe point. Killed all feeling in my hands in no time. Next, it made second just a little too high and third a bit too low for the GA mountains. I had it back in the toolshed the next day.
Added BBs to the bars and the vibration's no longer a problem. Now, at 15/48, she's perfect for the tight roads in them hills.

Whatever floats your boat...
Marc/Douglasville GA

[B12Teuton]

15/48 was what I did too.  Great in the hills and it now above the vibe range on the highway.

[Steve]

Manny,

I thought you went with the 15/47?

B12Teuton
(5/30/04 9:30 pm)
Re: chains/sprockets

Remember that this mod will give you a speedometer error of around 15%.
It's great for around town. I have a 15/47 on my 01B12S.
Manny

Anyways, I love the 15/47!

Steve

[scooter trash]

Sorry I'm so late but I have a few questions on this subject.
If you have to grind the front case to put the larger sprocket in why not just put a smaller sprocket in the back?
How low can you for before you really mess up a good thing?
I have a 00 1200 and want to do the same thing. I don’t care about fast starts and wheelies I’m a long distance rider and need fuel mileage and lower rpm at high speed.

[tacoman]

You can do a combo.  On my B6 I went up a tooth in front and dropped two in the rear.  This made it much more hiway friendly.   The sprocket cover mod is about a 10 minute job with a dremel tool.

[ray nielsen]

One reason for a larger front sprocket is longer chain life.  I have some old engineering books on chains that recommone NOTHING smaller than a 17 tooth sprocket for best life.

I can tell you from experience on a Kawasaki W650 and my Bandit 1200 that it appears to make a small difference.  On the W I got about 38K miles on a chain and sprocket set and the Bandit at 11,500 miles has had only two minor chain adjustments, one at 2500 miles the second at 11,000.  

When a chain moves around a sprocket it isn't really a smooth rotation, rather a series of straight lines in what's called a chordal arc.  The tighter the arc, the greater the stress on the chain.

[scooter trash]

Sounds good. thanks for the info.

 

[Elmojo]

Thanks guys, all good info.
I plan to do the swap as soon as I can get my lazy butt to Ron Ayers to order the gasket.  I'm hoping this will pick up a few MPG and fix my annoying oil leak at the same time.

Ride On!

Mike P.

[stetracer]

hey Manny,
 you said it changes the speedo thats only on 2nd gen. Bandits. My 98 1200 is cable driven off the front wheel

     J.D.

  and I agree with you What Gasket?

[Elmojo]

Hey guys,

I finally got the new gasket.  Yeah, I know, what gasket?
From the exploded diagram I originally looked at, it appeared that the sprocket was inside the large round-ish cover on the lower left side of the engine.  Now I know that this is not the case.  However, I still need that gasket, since it's the one that sprung a leak after I switched to synthetic oil.  Suszuki calls it the starter gasket, in case anyone is wondering.  I have the new gasket (only $6.20 from Ron Ayers!) and a 16 tooth sprocket from Sprocket Specialists.  I plan to swap out both at the same time just to save a few prep minutes.  I'll post results for anyone considering the same mod.

Later on,

Mike P.

[Bazza]

I just went to a 15-46 combo and do like it. Gave the bike a little more kick off the line and improved highway vibes.

The only problem I did have was that I had to add an extra link which placed the chain tensioning all the way back to the minimum position. Things will be fine I am sure after the 1st adjustment.

It really did not affect my speedo to the point where I am seeking a speedo correction device.

[Daytona]

Hey guys,

I finally got the new gasket.  Yeah, I know, what gasket?
From the exploded diagram I originally looked at, it appeared that the sprocket was inside the large round-ish cover on the lower left side of the engine.  Now I know that this is not the case.  However, I still need that gasket, since it's the one that sprung a leak after I switched to synthetic oil.  Suszuki calls it the starter gasket, in case anyone is wondering.  I have the new gasket (only $6.20 from Ron Ayers!) and a 16 tooth sprocket from Sprocket Specialists.  I plan to swap out both at the same time just to save a few prep minutes.  I'll post results for anyone considering the same mod.

Later on,  
Mike P.

 


  Hey "Mike" how did it turn out??? waiting to find out if i should follow your lead!