Hi Stanley, it’s cool to see you care for your father. There are bikes especially made for seniors. Try Bikes without cross bars, it would be easy for him to get on and off. Your father might be hesitant as he is starting after a long time. Make him ride around the block, you too join him, after he feels comfortable you both can ride longer distances.
Have you considered Recumbent bikes. It’s very safe and doesn’t cause any strain on the back. Will get little time to get used to it. After that it’s fun to ride.
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