When the key might break would be leaving a stoplight. I re-arranged the cogs on a new Winner recently and put several miles on same. Some nice hills,and hi speed cranking thru all the gears to get all the cogs snugged down tight. Well I came to a stop and thinking the way clear I eased out right in front of a fast car. I did the mash of my life to get across the street, and felt one, or more than one cog and fw body take up lots of slack that I didn't think was there. My legs were built up originally by York BarBells in Powerlifting competion. So if I had a weak point it should have popped then. Dickey Greer West Monroe,La Dickey's Recreation Room