Originally Posted by
Jakedatc
in that age of bike i'd be more afraid it was an odd size like 26.8mm that you forced a 27.2 into.
I surfed Sheldon Brown's website for awhile and my Bridgestone 400 has a 27mm diameter seatpost. I was joking about it taking 3 days haha. It takes about 1 minute for me to get the 300mm seatpost all the way down into the downtube. I would have kept using the Sakae/Ringyo CT P5E which I can fit in about 20 seconds but it was all perma-dirty (no signs of rust) from 30 years of use.