[roadrash194]

I have a 06 999S and I want to order a new chain and sprockets this weekend. The gearing seems to be alittle tall plus I don't think the bike would pull redline in 6th gear anyway,and I don't plan to on the street. In the mountains it seems like you are in 1st, 2nd, or 3rd gears alot,so I wanted to go up in the rear to a 38 or 39. I don't think I'll lose much topend anyway,so what works best a 38 or 39?? Thanks

 

[c5367ss]

39. You'll have a theoretical top speed of 160mph at 10k rpm, based soley on the ratios. With the 38, you get 165 @ 10k.

For comparison, the stock 15/36 combo has a theoretical speed of 174.

 

[c5367ss]

I should add, that these number aren't taking into account wind resistance. You could very well hit an aerodynamic brick wall at 150 in any of those combos.

 

[NCRick]

There is a magic number on the Ducatis; when in doubt, add 2 teeth to the rear sprocket (from the stock ratio). Even one tooth extra on the rear helps a good bit. I really do not have any experience with the 999 but going down one tooth on the front or 3 on the rear is normally a bit too much for road use where you are spending anytime at all on the highway.

With the 2:1 primary that is the 2.6:1 ratio and with the and 2.8:1 for the 1.85:1 primary; for the air cooled motors is a happy place. The 4 valve motors have the power up a little more and rev more so that is why the factory gears them higher. Guys who ride the 999 in conditions similar to you can give you feed back but I would try the 15/38 if it were me. (2.53:1)

 

[roadrash194]

I have heard alot of people talk about 1 down in the front,but I would think that with the chain making a tightier bend it would wear faster. I want to go to a 520 setup so I figured that it would be better to go up in the rear instead. I thank everyone for the info and I think I will go with the 38 as it is a good all around choice.

 

[NCRick]

The 14 countershaft sprockets are not expensive. I have a Sprocket Specialists one we sell for $10 if you have chain life left, put on one like that and try it till the chain is shot. then you will know. If you are going down the road hunting 7th gear all the time or 1st is not so handy in the twistys, then adjust to the 15/ what ever you want.

 

[pak996]

I have heard alot of people talk about 1 down in the front,but I would think that with the chain making a tightier bend it would wear faster. I want to go to a 520 setup so I figured that it would be better to go up in the rear instead. I thank everyone for the info and I think I will go with the 38 as it is a good all around choice.

Roadrash is correct in his thinking here. I have a 40T 520 setup. After all, how many times are you hitting 150, unless you are a consistent track rider, with plenty of straight or huge sweepers.
The real trick setup is to take a 748 close ratio gearset and drop it into the 996. It cures all the problems of the spread between 5th & 6th gears, and breaths new life into the fun factor of the bike.

 

[brianmdavis]

I have a 999r and dropped one tooth in the front. At the same time I added a 57mm Termi system. I'll tell you, with the added power from the exhaust, the 14 in the front did nothing. I'm going up 2 in the rear. From what I'vre read over the years, and all the folks I talked to, the commom theme on 999's is one down in the front and two up in the rear...Seems to be the perfect set up for street. I tried to save a buck...