Seat Post Size

[Quemal]

I have a 1982-84 Univega Gran Turismo. The seat post is original. One of the bolts that attaches the seat to the post is stripped. The seat appears to be holding, but would like to replace it. My question is:
How do I determine the size of the post?

[DaveM]

Many seat posts will have the size marked down toward the bottom where it inserts into the frame. According to <a href="http://www.sheldonbrown.com/seatpost-sizes-m-z.html#u">Sheldon Brown</a> it should either be a 26.6 or 26.8. If it is not marked and you have good calipers, you can try to measure it. You may be able to replace just the bolt depending on whether the piece it thread into is stripped as well. Any bike shop should be able to give you a quick measurement as well.

[Quemal]

Thanks for the info, since it is RAINING here in sunny SoCal. I should be able to take is apart and look.