Originally Posted by
Homebrew01
Many people may not know how to measure a bike size. A simpler number to ask for might be "standover height" .... the distance from the top tube to the ground. They can grab a tape measure or yardstick and easily measure that. You want a number that gives you an inch or 2 clearance in the crotch when standing over the bike..
It's a good ballpark idea if you don't have an actual frame size, but is not always a direct comparison and may not apply to everyone. I have short legs and more height in my upper body, so if I chose my bike based on standover height, I would feel cramped like I was riding a kid's bike. I actually had one like that at one time. I hated it, but my daughter rode it when she was 12 and it was great for her.
It's hard to know what will fit best until you've used it for a while. For $30 he can't go wrong as long as he can swing a leg over it. If he later decides to buy another bike, he'll have a good idea of what size he needs.