I’m buying a tricycle for my elderly mother. It will just be used for leisure riding and not for heavy loading. There seems to have several tricycle wheel diameters like 20”, 24” and 26”.
Which size is the best for stable and easier riding?
It is much more depends on your mum’s body frame. If she is petite, you might want to get her a smaller wheeled trike. Most tricycles come in two major type, the upright and the recumbent. For elderly people, a conventional upright tricycle would be just fine and more comfortable. And the price is cheaper too.
Generally, larger wheels roll over imperfect surfaces easier than smaller wheels. But, smaller wheels are stronger than larger wheels. Other than that, all else are just being equal because tricycle is basically a safe and stable vehicle.