Recommended Sprockets for Ducatis

[Shazaam]

Questions come up regularly about recommended sprocket changes and the required chain lengths for superbikes. Here's my recommendations for general street and track use.

http://home.san.rr.com/shazaam1/Recommended.jpg

Some of you are missing an important point about gearing. Different Ducati models have different different red-lines, primary drive ratios and different transmissions. So they require different sprockets.

For example, 916’s and 996’s both have the same standard-ratio transmission, but the 916 has a 2:1 primary drive ratio where the 996 has a 1.84:1 ratio. So the answer to the initial question about the best gearing will be different for the 916 and the 996.

So a positive result with a particular sprocket combination on (say) a 998 doesn’t often translate to a model other than a 998.

There's a "sweet spot" - around 4,600 RPM @120Km/hr in 6th gear for liter displacement superbikes, a little higher for 74X's. Obviously, faster tracks will require rear sprockets with fewer teeth, slower tracks more teeth (and possibly longer chains.)

I strongly recommended NOT changing the stock front sprocket or chain size for safety reasons. Just my opinion.

[Gemcoska]

Shazaam,

Thanks for the guide... I was about to order a new rear sprocket and it seems that the majority of this forum all go with 15/42. It would make sense however that each model would have an ideal sprocket size.

I would like to confirm that I should be going for a 15/43 sprocket combination with a 525 98-link chain, or is that only for the 996S...

Also, I read in the forums that an odd/even sprocket tooth combination would reduce wear. Is there any truth in this?

Lastly, do you have any recommended online stores to buy the chain and rear sprocket.

Thanks,
Rob
01' Yellow 996

[VinceS]

I have found the sprockets from these people www.chaingang.com.au simply don't wear out! They really have got their act together for the metallurgy and manufacturing of sprockets. After 54,000km on an ST4S that enjoys a fair bit of throttle stop work I can't detect any wear to the 41T rear I bought from them. Whilst that may appear unlikely it seems to be the case! Probably helped by the simultaneous fitment of a Scott-Oiler that I later converted to the much better Pro-Oiler system (www.pro-oiler.com).

Re ratios I changed from factory 15/38 to 15/41. With long experience I would say the optimal ratio is 15/42 for a standard ST4S with slip-ons and an opened up air box. However, with a dyno'd on Power Commander and DP lightened flywheel I now think the 15/41 is ideal, perfect!!!

(I once read that the fun to be had riding a motorcycle is exponentially proportional to the total time spent on the throttle stop - and have long learned the simple truth of this!)