My B'ton I went Double planetary .. 54t MD 15t hub BSR ..double shift 43.4 to 30.8 can go at any speed , bogged on a rise for example ..
6, 5, 4 .. double shift
throwing hub lever from low to high and tapping the mountain drive shift button shuttling though the BB, into low range..
3, 2, 1 (17.4)
The 57.9 is the fine pootling along gear..
(sheldon's chart does not transfer well.. given my computer skills )
2.5:1, reduction gear low, a 54t acts like a 21.6t as cranks turn faster than the chainring.. through the gearbox..
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