I am looking at a good alloy road bike, cannondale caad12. It is a good deal but there are some dents all the down the seatstays, not major but not nothing. Is it safe? Does it affect the bike? Should I still consider buying it?? Thanks Charlie
Aluminium doesn't like dents. Steel bikes can cope with enormous dings, but on an aluminum frame the same dent would weaken the metal, and undenting it makes the weakness worse.
It may be worth acquiring as a parts donor, if the groupset/stem/bars/wheels are in reusable condition.
Ultimately it is your decision.