Originally Posted by
sid_rana
Thanks, melville. It's a relief to learn that other bikes are also abused as such.
However, the stress I place on the frame and seat post, when I ride the bike, is vertical. Whereas, crank and pedal tightening places a rotational stress on the frame and seatpost; more so when it is suspended in the air with the seat post clamped.
Actually, unless your seatpost goes straight up perpendicular to the ground (probably not) the force you put on the post from riding is similar to the force the mechanic put on it. Seatposts slant backwards so you are putting vertical and leverage force on it when you ride. Imagine the amount of force generated when you hit a good sized bump with your butt on the saddle.