This doesn't make any sense.
If it's a 26.4 mm seatpost, then your 1" seatposts should not be too big for the seat-tube, because 1" is 25.4mm, or 1mm SMALLER than the existing seatpost.
Try measuring your seat-tube, and maybe try using lots of grease on a 1" seattube and try inserting it again.
Originally Posted by rumrunn6
I would like to replace this eatpost with another that is a few inches longer. This one is about 8" long; exactly 1" wide and has this TEXT engraved into it:
ON THE HEAD:
LAPRADE with an S/R logo
ON THE POST:
with an S/R logo
It's on an '80s era Scwhinn LeTour.
I would like a longer one for height a security.
My other 1" seatposts don't fit. The tube on the bike is tad too small for them even if they start to feed in.