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Old 08-13-13 | 03:35 PM
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overbyte
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Joined: Jun 2007
Posts: 250
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From: Santa Cruz, CA, US

Bikes: 3 folders, 2 recumbents (1 is electric), 1 recumbent trike, 1 touring, 1 mountain, 1 road bike -- So many bicycles, so little time.

Gear inches of the Schwinn Loop versus some other 20" wheel folders

I marked one and counted the gear teeth. The crank chainring has 40 teeth. The rear freewheel set has 13 to 28 teeth, which matches the 7-speed "M" cassette at Sheldon Brown's calculator: http://sheldonbrown.com/gears/.

His site calculates that the Loop's gear-inch range is from 26.7 gear-inches in lowest gear (#1, the largest rear gear) to 57.5 gear-inches (#7, the smallest rear gear). This gives ground speed at 90 crank revolutions per minute (cadence) of about 15 mph. For more range of gear ratios, I suppose one could replace the rear gears with the "7-speed megarange freewheel" which has 11 to 34 teeth, giving gear-inches from 22 to 68, which has better hill-climbing and top speed of 18.2 mph at 90 rpm cadence.

For comparison, some other 7-speed 20" wheel folders have these gear-inch ranges:
  • Dahon Vitesse D7: 32 to 79
  • Dahon Mariner: 34 to 92
  • Tern D7i: 32 to 79
  • Citizen Miami: 32 to 64 (6-speed)
  • Brompton (16" wheels, 6-speed, lowest gear-inch range option): 29 to 88.
So indeed, the Schwinn Loop (27 to 58 roughly) has gearing which more favors hill-climbing (lower gear-inches) than other common folding bikes. To me, that's more important for touring than speed on flat ground. After all, getting up those hills is the killer, not a lack of downhill coasting speed (which the Loop does fine) nor a lack of flat-out speed on the easy roads when you are trying to enjoy the getting there, not just the destination.

Last edited by overbyte; 08-13-13 at 04:30 PM. Reason: Update with Brompton.
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