A balloon catheter system for the intraluminal advancement of conventional guidewires beyond partially or fully occluded or stenosed lesions in body passages, such as CTOs in the vasculature, is provided. Balloons are provided. In certain embodiments of the invention, a balloon having relatively thickened proximal tapers is provided. In certain embodiments of the invention, balloons having a tapered midsection are provided. The balloons are preferably useful with crossing balloon catheter systems. In certain embodiments of the invention, the balloons preferably reduce or minimize trauma to the vascular wall or wall of other body passage in which it is used.