Desmo Times Product 102a - Countershaft Sprockets

STEP 1 - Steel Countershaft Sprockets:

There are 2 styles of countershaft sprockets used on Ducatis. On the left is the style A used through 2002, with threads for the outer retaining shim. Style B of countershaft sprocket (right) doesn't have threads for a retaining clip because it uses a large nut to retain the sprocket. The Style B sprocket is also .5mm thicker from front to back (offset).

Look at your countershaft prior to ordering

NOTE 1: 800cc and the MS4 motors sometimes have a different offset to the sprockets. In this case, mount the sprocket with the flat side towards the motor.

NOTE 2: Dropping a tooth in the front sprocket yields the same approximate results as increasing the size of the rear sprocket 3 teeth.

NOTE 3: It is recommended that the chain be replaced when replacing the sprockets. Worn sprockets accelerate chain wear by stretching the links in a chain.

Steel Countershaft Sprockets - $23-$39

STEP 1 - Steel Countershaft Sprockets: There are 2 styles of countershaft sprockets used on Ducatis. On the left is the style A used through 2002, with threads for the outer retaining shim. Style B of countershaft sprocket (right) doesn't have threads for a retaining clip because it uses a large nut to retain the sprocket. The Style B sprocket is also .5mm thicker from front to back (offset). Look at your countershaft prior to ordering NOTE 1: 800cc and the MS4 motors sometimes have a different offset to the sprockets. In this case, mount the sprocket with the flat side towards the motor. NOTE 2: Dropping a tooth in the front sprocket yields the same approximate results as increasing the size of the rear sprocket 3 teeth. NOTE 3: It is recommended that the chain be replaced when replacing the sprockets. Worn sprockets accelerate chain wear by stretching the links in a chain.
Style Pitch Tooth Count Quantity:

Steel Countershaft Sprockets: $23 for style A, $39 for style B
Q&A: Why is there a price differential between the syles of sprockets? The older style sprocket is now available from a foreign supplier - JT. The grade of steel is as hard as those domestically available, so I use them and recommend them. Style B countershaft sprockets are AFAM brand and are made in the USA. How can I tell what style countershaft sprocket I have? Remove the countershaft sprocket cover and look. If there are two screws and a plate securing the countershaft sprocket, you have the old style. If there is a large nut holding the countershaft sprocket, you have style B. Style B countershaft sprockets are secured by a Nut with a large washer beneath it. Can I reuse the washer? Yes, you can reuse the washer. Ducati takes one edge of the washer and bends it over the nut to secure it. If you carefully bend the washer edge back with a wide screwdriver you can reuse it. You sell 14 tooth countershaft sprockets. I thought these were too small and that such sprockets brought the chain too close to the chain slider on swingarms. I've been running 14 tooth countershaft sprockets for a decade on my bikes and on customer bikes and have never had a problem with chain slider wear. How much of a difference will switching to a 14 tooth countershaft sprocket make? Dropping a tooth on the countershaft sprocket yields a similar result compared to adding 3 teeth on the rear sprocket. It usually drops 500 rpm off the bike at cruising speeds. So, if before you were doing 70 mph at 4000, you'll now pull 4500 rpm at 70 mph. How do I tell what pitch my stock countershaft is? 520 pitch sprockets are 5.9mm thick, while 525 pitch sprockets are 7.2mm thick (measurement is of the teeth contact area, not the entire thickness of the sprocket). How can I tell when it's time to replace my countershaft sprocket? I recommend replacing countershafts when the teeth of the sprocket begin to fish-hook. The teeth will start to appear to be bent as one side wears more than the other. Notice the fish-hooking teeth of the worn countershaft sprocket (below), and the tooth that has sheared off.