I'fe just finished building up a mid-80s Raleigh frame into a singlespeed, and eveything's working so far except the seatpost. Basically, the post itself is bent about halfway along its length, which means it won't go far enough into my frame and my saddle's too high. I have a plan, however. I intend to cut off the bent section and use the remainder of the post, which should be long enough, as the frame is HUGE and I only need about 3-4 inches of post. Before I break out the hacksaw, is there a way to straighten the seatpost? It's made of fairly thick aluminium, 27.2 mm OD.

While I'm on the subject, is the "minimum insertion mark" on a seatpost there because a seatpost inserted less distance than that will be insufficiently clamped into the frame, or because a seatpost clamped below that point is in danger of bending just above the seat lug due to the large turning moment about the point where it clamps in? I've often wondered about this...