Wondered if anyone who has 17 tooth front sprocket (1 tooth up from oem) has metal clunking sound from the chain/clutch. Checked chain slack on 4cm, front sprocket bolt tight. Readjusted chain down to 3cm which is tighter than the 3.5cm spec but should be ok as doing high miles 500m week at the moment. All I could surmise is given the bigger front sprocket less chain clearance below it where the chain rolls over the chain guide, maybe the slack chain is clunking on clutch pulls. On 17000 miles 1st chain trying to last until the rear tyre needs replacing.