Guess that when 24" bikes become very popular, 22" bikes will come out, as a good balance between 20" and 24". Then when 22" bikes become popular, a 21" bike will be made so that people can ride a bike which has the advantages of a 22" and 20" bike. I thought Jake would mention titanium holes but it looks like Wright Pads have taken over his world already. Still, I guess nobody is stopping us from having fun on a good old fashioned trials bike? The only thing is that they don't ride too well. The 231 X-Lite had 400mm chainstays and a 1040 wheelbase if I remember correctly. Now that's a bit wrong.