Up front, I haven't been on a bike in 25 years.

I'm 5'2" and the store I just bought my bike at said that is the dividing line between a 24" wheel and a 26" wheel. It's not a dedicated bicycle shop so the guy wasn't a bicycle specialist. He brought down the 24" first and held it while I got on it. The seat to ground length fit well so I bought it 3 days ago. Once I got it home, I tried it out, and it just felt wrong. I felt like my knees were chest level while pedaling, even though they weren't. Since it only took minutes to regain balance and steering, I tried to take it on a long ride. After a third of a mile I was gasping for air and could barely move my legs.

Since it didn't feel right, I took it back yesterday and got the 26". Got on that thing and it felt so good. My practice run in the parking lot turned into a 2 mile ride and at the end I was breathing a little hard, nothing significant, and my legs ached a little. Today I was sore all over when I woke up but my legs hurt the least. The only thing keeping me off the bike today was being saddle sore, and I bought a memory foam seat cushion this evening for help with that.

However someone I know online says she runs a motorcycle and bicycle safety course and she's really, really worried about the fit. I have the seat all the way down, and I'm on my tippy toes if I put my feet on the ground while on the bike. I'm pretty sure it was that same way when I was a teen and practically lived on my bike. She's concerned that my inability to put my feet down flat is dangerous, since it will affect my ability to balance when I stop. But clearly a smaller frame that enables me to put my feet flat on the ground is all wrong for me, since I couldn't manage any bit of distance on it.

Should I be concerned about how high up I am? My intention is to stick to sidewalks and city streets, not going off-road. And like I said, I'm certain this was the same fit when I was young and I did a lot of off-roading then, a lot of falls, and I survived with only some scars and great stories to go with them.