Originally Posted by
Retro Grouch
How slow can you go? At some point your climbing speed will be so slow that you'll likely have trouble staying balanced. I'm thinking that 20/42 will approach that point.
With a little practice, anyone can go 0 mph... as in a track stand. A 20/42 gear at 40 rpm with a 27" wheel has a speed of 1.5mph. 60 rpm returns a speed of 2.3mph. I've done lots of climbing at 3 mph off-road where balance is much more difficult. It's not all that to travel at that speed on pavement.