I have a 1980's schwinn sprint which i have converted to fixed gear (i would have liked to keep the gears but that discussion is for another time). I would like some advice on how to measure the diameter of the seat post and handlebars as i would like to replace them, i have searched around but cant really find anything on how to do it.

Thanks

Chicken

The handlebar will be 25.4mm (1") at the center stem clamp, and 23.8mm (15/16") everywhere else. The seatpost I'm not sure of, but you can use a caliper to measure. If you don't have one, the cheapest one I know of is this: https://www.google.com/search?q=6%22+...borfreight.com

Thanks, is there anyway can run a 26 in the stock steam or do i have to get 25.4mm bars

If you don't have a caliper, you can employ basic geometry: wrap a strip of paper tightly around the seatpost, use a sharp knife to mark where it overlaps. Lay flat, measure accurately in mms, divide by pi (3.14) and that's your diameter. A caliper is better, but this will get you close in a pinch. Do it a couple times and average the results.

Or you can cheat and pull the old seat post out. It may have the size inscribed on it.