Originally Posted by
chaadster
Ah, I was thinking that the X20 used the Capreo hub design to fit a 9t cog.
Even if a 20"er has the same gearing as a 700c, in any given gear pedaled at the same RPM, 700c will travel a greater distance, so a 20er needs even more gear range than a 700c bike to keep up. Outside of one-off record attempt small wheelers, I've never seen a 20" with gearing to match a 700c's capability.
The high end of a roadie, sure. But that sort of gearing is only needed with high speed downhill racing. On level roads, a 20" bike with 60t ring and 11t cassette is more than adequate. My Ti Swift's highest gear is 109" while a roadie with compact crankset has just 1 extra higher 10% step for 120".
So maybe you won't keep up with a roadie on a long downhill while they are cranking massively but for all other road riding 109" is just fine.