amdx wrote:

I have one of the Harbor Freight 7 x 10 lathes.
I have a bicycle seat post that I want to reduce the diameter by 0.025".
The spindle head is to small to accept the post, the bed is to short to
use the tail stock.
Any clever ideas how I could use this lathe to do the job. The post is
aluminum.
I took it to a machine shop, he laughed and said, "I've already spent
more time on this than the part is worth."

It sounds like this lathe is just the wrong tool.

Clamp the seatpost on allthread in a drill with some nuts and a washer.
Run that with the left hand with the end of the allthhread on a block of
wood. Angle grinder with flap disc in the right hand. Take passes back and
forth.

You'll be done in a few minutes for quick and dirty OD removal.