The title of this message is simple enough. If you try hard enough you will break steel cottered cranks. I have a theory that some pedalling styles break cranks. I used to break cranks regularly. Yes, I fitted them with torque spanners and used pedal washers etc., I now use modern cranks and they do not break. The problem has shifted itself on to seat tubes, three in as many years, just above the lower butt (all of them steel frames). I do not pedal big gears, in fact I have never owned anything bigger than a 52 ring. I know of other cyclist who regularly would break cranks and others who never did. Is this a pattern that repeats itself else where in the world?
Regards
Martin Coopland