Originally Posted by
SJX426
Corruption like rust or gunk is one option. I would ask him to shine a light down the ST and explain what he thinks the reason for the hangup based on what he can see.
This was my first thought as well. Once had a seat tube so dirty internally that the seat post size went up by .2mm once it was clean.
Was a very neglected bike.
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A race bike in any era is a highly personal choice that at its "best" balances the requirements of fit, weight, handling, durability and cost tempered by the willingness to toss it and oneself down the pavement at considerable speed. ~Bandera