I know the feeling because I've had seatpost slippage on several bikes (I'm 100 kg +). The first time I ran into it, I also incrementally cranked the bolt down tighter and tighter (without helping the slipping) until it snapped. With that in mind, I guess if the bolt snaps it means the seatpost is undersized (or the clamp is deformed), which causes the bolt to bend as you try to tighten it.
Anyway, each time I've managed to solve the problem by going up a seatpost size, even if it means ignoring the manufacturer's recommended size. One time the required size didn't seem to exist, so I used a wrap of 0.2 mm thick steel shim, which also worked. In my hands, none of the other commonly suggested methods (like beer can shim, abrasive rub etc.) have ever helped... but it could just be a question of weight. Good luck, and let us know how you end up fixing it. -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To post to this group, send email to rbw-owners-bunch@googlegroups.com. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
