US Patent 9533731 Bicycle handlebars with portion with doubled section

Handlebars having a master tube, two handgrips at opposite ends of the master tube, a stem for attaching to a fork, and at least one portion with doubled section, the cross section of which comprises an upper outer wall, a lower outer wall, an upper inner wall and a lower inner wall. The upper outer wall is distanced from and joined to the upper inner wall, the lower outer wall is distanced from and joined to the lower inner wall, and the upper inner wall is distanced from the lower inner wall.