Aprilia SL-1000 Final Ratio -- Rear Sprockets

In the USA, the Falco comes with a 41/16 final ratio. It's geared for 173 mph or so, at least that's what I hit on the dyno. The Mille comes with 42/16, so swapping a Mille stock sprocket is an easy way to raise the final ratio and still keep your stock chain.

A slightly used Mille rear sprocket was easy to come by, but the downside is that it's a steel unit and is quite heavy. At least it will last a while. You can order aluminum sprockets in the USA at Sprocket Specialists.

The Falco and Mille use the same rear sprocket patterns

Replacing the sprocket is easy. Remove the rear wheel, and pull the sprocket carrier out of the cush drive (there's nothing holding it in but friction). Put the sprocket in a vice and use two wrenches to remove the five M10 nuts from the dowels holding the chainring to the carrier. When you replace the sprockets, use Loctite 243 (blue) if you don't have lock nuts. Torque the nuts down to 50 N-m.

This is a good time to verify wheel balance. My wheel was off. The heavy spot was opposite the stem, red dot, wheel weights and new tire patch. Go figure?

Continue to some drive force charts with the new ratio...

Update: August 2001
There's now a source for front sprockets... read more.

Go back to the Falco home page.