I'm building a Greenspeed GTR for s tour this summer. I talked with Ian and Paul Simms (Mr. Greenspeed themselves) they said theat they've tested both 20 and 26 inch wheel and found no advantage to a 20 inch wheel. The first Greenspeeds were 26 inch rear wheel. A 20 inch wheel is stronger and lighter. 20 inch wheel mean a lower gearing.

If you want speed talk to Tony Stark (Iron Man). Get him to build you a pair of super strong knees. Then put a 100 tooth front chainring an go babiieee!!! Just joking. I'm notintersted in speed or trying to keep up with people. Why not let your boys do their spped and find someone else on the tour that will ride at your pace?