Good afternoon, I have a Derbi GP1 250 as well as 125er. When pushing the 250er (engine off) it clacks. Got the chain in assumption. BJ 2008. At the Derbi 125 it clacks strongly when driving. Was at a workshop Faber with request for check. Result. Drive belts changed there worn off. Ok but it still clacks quite. According to service manual two chains are installed. My question now, it is normal that these chains clack at the Derbi GP1. There is a lack of half-timber workshops in Österre for Derbi and Faber my scooters are called exotic. Does anyone have more experience with them than I do? Thank you. Lg