Originally Posted by
jgwilliams
There's also the option of 20/20 - see the Velotechnik Grasshopper. Good compromise between speed and practicality.
Ii wouldn't quite call it a compromise between speed and practicality. Dual-26s are perfectly practical. I'd go farther and say that 20" drive wheels introduce other problems, such as gearing; so in some ways dual-26s are more practical too. But they are smaller than dual-26, so if size is an issue, that's their advantage.