Every tube used in the construction of a Marin bike begins life as a simple, plain round tube. Butting is a process by which a plain round tube has material removed in order to make it lighter without sacrificing its useful strength. This basic process lies at the foundation of all of the shaped tubing used on Marin bikes. In the case of a frame tube, it is logical that the material needs to be thicker near a weld, since the material will experience the greatest amount of stress and strain in this area. However, thicker material adds unnecessary weight towards the middle of the tube, and adds very little to the overall strength of the frame. So the tube is "butted", which makes the wall of the tube thinner towards its centre, and thicker near the welded junctions. Butting specifications are different from model to model, and from size to size within each model. For example, a frame designed to be used by a rider that is over 6 feet tall will need to have a different butting profile than a frame built with a 5 foot 2 inch rider in mind. Virtually every tube on every bike in the Marin Bikes line has been carefully considered, and butted accordingly.
While different sized frames are made of different length tubes, many manufacturers save time and money by using the same specification butting in different sized bikes. Marin, however, "custom butt" their tubes for each size bike. This attention to detail allows Marin to build exceptionally light frames with class-leading durability. Custom-butted frames also feel much more dynamic, accelerating faster and cornering harder.
