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I have seen a number of posts advocating going to a 42 tooth sprocket on the rear. If I do this, do I need to change the chain as well? Pros and cons of this mod? Any recommendations on the best source for a replacement sprocket?chain?
Thanks, Jack.
 

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oldguy said:
I have seen a number of posts advocating going to a 42 tooth sprocket on the rear. If I do this, do I need to change the chain as well? Pros and cons of this mod? Any recommendations on the best source for a replacement sprocket?chain?
Thanks, Jack.
Many folks who complain about their stock gearing have an ST4S, which has a 15/38 stock sprocket ratio, if I'm not mistaken. Fortunately for you, the ST3 is geared with a 15/42 setup, which most people end up going to; or at least in that neighborhood of ratio. So, you're all set! :)
 

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oldguy said:
I have seen a number of posts advocating going to a 42 tooth sprocket on the rear. If I do this, do I need to change the chain as well? Pros and cons of this mod? Any recommendations on the best source for a replacement sprocket?chain?
Thanks, Jack.
Most of the recommendations regarding a 42T rear sprocket are for the ST4s, which comes with a 38T OEM rear sprocket. I don't know the size of the ST3 OEM sprocket or which size suits it best.
I have read that you should change both sprockets and the chain at the same time. If you are happy with the performance of your bike right now, I would wait until you need a new chain before experimenting with a new sprocket combination.
 

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Accoring to the MY2004 user manual on pg.90, the ST3 has 15/42; same as my ST2.

If you're new to Ducati, you should just leave it in a lower gear. I don't use 6th unless I'm above 65 MPH. I find that when I'm on a zesty ride, usually on the highway, and shifting to make traffic shrink in my rear view mirrors, I often find myself looking for a 7th gear. So I don't think that 15/42 is all that bad.

As a rule of thumb, don't use the engine below 3500 rpm, this or lower is usually lugging the engine, unless you're going down a hill, dn just maintaining a certain speed.......it's much happier around 4K. I betcha this is why a lot of the ST3's shake their horns off.
 

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My 05 manual states 15/42. No need to change the ratio. Well I'm not going to.
 

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Good thread. I was wondering why i'm going so fast in 6 at 5000 rpm and i see that i have a 15/40 setup. Kinda crazy realitive to the Monster. I seem to never get out of 3rd gear on secondary roads. According to the gear calculator, theoretically i can top out a 167 mph. Yahoo!
 

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I think that you will be alright with your oem chain. I am running a 14/43 so thats down 1 in front and up in the rear. And I love it. My bike pulls smoothly all over the tach and I actually use 6th gear every now and then.
 

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FatguyRacer said:
Good thread. I was wondering why i'm going so fast in 6 at 5000 rpm and i see that i have a 15/40 setup. Kinda crazy realitive to the Monster. I seem to never get out of 3rd gear on secondary roads. According to the gear calculator, theoretically i can top out a 167 mph. Yahoo!
Yep. For mine I originally (obviously) had the 15/38 factory gearing with the 525 pitch chain. I went 14/40 and kept the factory 525 pitch chain as it was in really good shape. Now 5000 rpm gets me 84 mph on the speedo in 6th gear. I can actually use 6th now on the highway below 90 mph...hurray! No, I don't have any swingarm issues with the reduced count on the countershaft sprocket. :)
 

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St3 14/42

I have a one tooth smaller cog (14/42) on the front and love it. Unlike previous posts i can ride fine below 3500 rpm. This gearing works well in city traffic and highway. I do use 6th gear on the highway regularly.

We are not too far apart (Leawood), so maybe we can meet and you can take my bike for a spin if you want to see the difference in the different gearing. PM me.

Raj
2004 ST3
 
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