Any idea why ducati went with the rear sprocket change instead of the front?

Dylzduc said:

This is the answer I got from AF1 racing who are awesome guys on the Aprilias.I just got my Race ECU sent out by them and below is their answer on the topic.I know they are different bikes but these guys are an amazing shop and their customer service is fantastic. AF1 knows their stuff.


Personally, I wouldn't run a 14t front. It's a very small radius to wrap a chain around and could cause premature wear and/or failure. Now, there is a whole science behind how sprocket diameters affect squat, anti-squat, chassis length, and chain torque, but for us mere mortals we're probably more concerned with chain/sprocket lifespan and convenience. If you have the chain length and room in the swingarm adjusters it is generally more advisable to run the largest sprockets you can for the desired ratio.

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Dylzduc said:

That might not have anything at all to do with what the Ducati tech is talking about on the 1199,and I don't think it does, but I wanted to check on the Aprilia as I'm making a change there as well.

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efna said:

Think leverage. I learned this racing mx. A larger diameter sprocket provides better leverage than a smaller diameter sprocket. Given any ratio combo front to rear always go with the set that has the larger front sprocket. For example. 14 front 42 rear and 15 front 45 rear are both 3:1 ratios. Go with the 15/45 combo. The larger 15 toothfront sprocket provides a better leverage ratio because of the longer radius. For those who have removed there rear wheel, what requires less effort, a short 12" ratchet or the 24" breaker bar?

There are other consideration too such as impact on rear suspension and squat during acceleration but this can be managed by changing the swingarm pivot height and thus we see one of the features on the R model.

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