Originally Posted by Sangetsu

I am sure there are fast group rides in your area, take your small wheeler and see if you can keep up. I've ridden a lot of bikes, and done more than a little competitive racing. My Birdy weighs 18 pounds, has the same components you would find on any $3k road bike, I have even set it up so the riding position is identical to my road bike, same saddle, same pedals, same bar width. It is very fast for a folding bike, but it cannot touch a road bike in regards to speed, and the difference is not small, it is huge. On a road bike, I am a competitive rider in any group, on a small wheel bike, I can't even keep up with the B team.

Racing associations didn't adopt the 700c standard because it was inefficient, or made the bikes slower. It has more or less boiled down to be the optimum size for racing. And a standard was needed so spares could easily be supplied. But group rides have no wheel size restrictions, you are welcome to see how your 20" bike fares against the big boys. If anyone else here has tried it, it would be interesting to hear your experiences.