I had the sprockets and chain replaced on the ST2 the other day and came to the following conclusions. 1. Be careful of the combination of sprockets used as the ratios can change 2. When then riding the favourite piece of road after refitment becareful because the engine note will be different with the different ratio and you can find yourself entering the corner in gear higher than you need or at least 20 km quicker than before. This has come about because I went from a 14 front 42 rear to a 14 front 41 rear. effectively changing the final drive from 3.0 to 1 to a 2.93 to 1. Now this may not sound a lot but be warned the engine note will be different for a given road speed. The standard gearing on the Duke at new was 2.89 to 1 so I still have better acceleration properties and is still ok bumbling along in traffic, I just have to get used to the engine note at certain speeds so I do not get caught out by the revenue raisers. :wink: :wink: I will say though it feels a lot nicer with the new chain on board.