Disclosed is a balloon catheter that can comprise an elongate support member, an inflation tube, a guidewire tube and a balloon. The guidewire tube can define a guidewire port at its proximal end, and can extend from the port through an opening in a wall of the elongate support member and distally through a first lumen of the elongate support member, in some cases to the distal end of the catheter. The inflation tube can be disposed over a distal portion of the elongate support member, a portion of the guidewire tube, a portion of the inner assembly, or any combination thereof, forming a second lumen. The distal end of the balloon can be attached to the guidewire tube and the proximal end of the balloon can be attached to the inflation tube. The inside of the balloon can be in fluid communication with the first lumen and with the second lumen, allowing the balloon to be inflated and/or deflated. The elongate support member can also have cuts in it. For example, the elongate support member can have apertures formed in it, or apertures and spiral cuts.