WHAT DOES ENGINE BIKE EXHAUST MEAN?

Jockey wheel: one among two modest sprockets in the rear derailleur that guides the chain onto the cassette【110cc bicycle engine kit】The 110cc 2-stroke bicycle engine kit is powerful and durable, which may speed up your bicycle to your utmost speed of 55 km/h, with fast speed, safe and stable, and good warmth dissipation performance.Handlebars