Well, there are varyng degrees of leg strength and leg usefulness at any age and, particularly, with advancing age. I am 61 and, thankfully, even if it takes several kicks, I still have the wherewithall to apply the force. It would seem that a person who could still give three or four good kicks on a well-tuned engine with a healthy mag may have a better chance of starting the bike than the electric starter (before the battery dies) on a poorly tuned bike that, maybe, has a sick mag. I guess my point is, if you think you need an electric starter because you can't do all the kicking reps it takes to get started, perhaps a tune-up and a mag rebuild is a better choice. For those who can no longer do any reps, we can be thankful to Steve for giving our mates the option to stay in the game. (Steve, it is clearly an excellent piece of engineering.)
Just for curiosity, I would like to know what the age is of the oldest person here, or known by those here (feel free to say "a bloke I know" even if it's you), that can still kick start an A7 or A10.
Richard L.