So, I'm thinking about a Xootr Swift as an upgrade from my Dahon Mariner D7, and checking out the gearing. I'm not a "gear nerd" and am trying to figure out if I understand the differences, which seem to go a little something like this:
50T x 11/30, 33" - 90"
Xootr Swift - Stock
52T x 11/28, 36" - 92"
Xootr Swift - Different Cassette
52T x 11/32, 32.5" x 92"
Bike Friday NWT 24-speed
52/42/30 x 11/32, 18.75" x 94"
700c Road Bike w/Triple
52/42/30 x 12/26, 33" x 125"
700c Touring Bike w/Triple
52/40/30 x 11/32, 27" x 137"
I assume the stock Xootr will be a little slower up hills than the Mariner, with a little higher top speed. The NWT's range seems to go very low (which makes sense for that bike). But it seems odd that some of the folding bikes with a single will have almost as low a gear as a 700c road bike.
So is it that the single crank loses a lot of efficiency due to the indirect chain in the low gears? Or that road bike designers are intentionally picking that gear range? And do a few inches on the low end really make a huge difference?
Last but not least.... Will moving from an 11/28 to an 11/32 on the Xootr (as recommended by flyhi46c) make for a more troublesome drive train -- i.e. more chain stretch, rougher gear shifting, higher chance of chain jumps etc?