I buy and sell a few bikes for fun, I had a vintage mountain bike on craigslist. A 365 pound 60 year old called me. I told him I thought the bike would work good for him, if he took it easy at first. He hadnt been on a bike in 25 years. When he arrived at my house, he looked at the bike got right on it and started riding lol I was little shocked, hopped on my bike to catch up with him in case he had a problem.

Anyway what they say about you never forget how to ride a bike is true. I think a 70 year old can get right on a bike and start riding.

"Get a bicycle, you will not regret it, if you live." - Mark Twain