It is possible , to 1,) spread the ears apart , until the slot is parallel, again,

and then with the next larger size seat post ..

2) get the frame tube bored out with an adjustable reamer to the precise fit of that new seat post

& have it by virtue of that fit take very little squeeze to make a secure grip '
& by having the ID smooth..

raising/ lowering the post should not leave scratches ..


I did this to use a 27.2 seat post in a frame originally with a 27.0 post in it..

May not be a butted seat tube .. but straight gage ..

[I have another bike built with out a butted tube set , straight gage 0.9mm wall it uses a 28.6 seat post]







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