Spring loaded Automatic adjust Chain Tensioner
This engine attach Automatic Chain Tension feature is a great enhancement over the standard clamp to stay fixed idler.
With this spring loaded tensioner you Never have to adjust chain tension again.
Pulley has ball bearing operation same as the standard chain stay model.
Keeps constant tension on your drive chain to overcome loose or stretched chains that will occur over time.
Attaches to the drive cover of any Chinese 2 stroke bicycle engine.