After some time, the control loop ✅ should be replaced. If this will be failed, the chain can jump over and a serious damage to the engine is a consequence. When a chain has to be changed, is depending on the type of the chain (simplex / duplex) and of its use and care. At our house you get duplex control loops with lock for R2V models up to 9/1978 and simplex control loops with lock for R2V models from 9/1978 as well as the suitable slide rail for the chain tensioner simplex. You can find chain tensioners in this category with spring or piston for simplex chains from 9/1978 and duplex chains up to 9/1978. If you determine an oil loss on the motorcycle, this might have something to do with leaking protective sleeves. We have protective sleeves made of stainless steel and the suitable punching pin for protective sleeves in the degrees 16 mm for R2V models up to 9/1974 and 18 mm for R2V models up to 9/1975. 16 mm punching pins were used until 9/1975. For R100 models with nicasil coated cylinders, we have also a piston ring set in our range.