Jockey wheel: among two little sprockets of the rear derailleur that guides the chain on to the cassette Hanger: part of frame or an attachment to the frame to which the derailleur is hooked up (see Derailleur hanger) Triple engines are characterised by high Center power and tonked high-speed power. https://gregoryqvwyy.popup-blog.com/34121003/a-review-of-bike-engines-explained