you can get shims for a fiver. most modern frames do not go below 27.2 so if you have a 27.2 post you can get a shim that will make it fit to a larger size seat tube.
if you want a negative shim then i think BRM sells them?
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you can get shims for a fiver. most modern frames do not go below 27.2 so if you have a 27.2 post you can get a shim that will make it fit to a larger size seat tube.
if you want a negative shim then i think BRM sells them?