estebe

I bought a used Surly Straggle bike yesterday in mint condition. All good, smooth riding bike, however I have a problem. Upon removing the seat post for greasing just to make sure I discovered that it is 26.8 mm instead of the 27.2 it should be according to the official documentation on the Surly website. The seat post just drops in the frame without any resistance and once in it slightly rattles around...

I happen to have a (cheap) 27.2 seat post around and tried to insert that (even with the clamp removed) however no luck, it won`t even get in 1 mm. Now, nothing seems deformed, the seat tube is clean on the inside, no rust no cracks no nothing. Question is what do I do now:

Try and get a better quality 27.2 seat post maybe that fits or just ride the bike as is and don`t worry about it? I rode the bike home when i bought it and and all seemed good, the seat post didn`t slip etc. I wrote Surly asking whether they ever made a Straggler with 26.8 seat post however I highly doubt it...

FBinNY 

The rattling of the 26.8 post seems to indicate it's too small. The fact that the 27.2 doesn't fit may or may not be meaningful, because the top of the seat tube may be pinched closed a bit from being on the 26.8.

Often the est indicator of seat post fit is the slot in the sear tube. With the 26.8 securely clamped, measure the top and bottom of the slot and compare. If the right post is in there, they'll be nearly identical. If the top is more than 1mm narrower than the bottom, the post is too small.