Tiltmanic has a Sugino double crank 74 BCD and 130 BCD ($500 ) with 27 T and 50 T Q ring 10% oval Chain-rings, and a 11 to 36 10 speed cassette on his new S30, which gives a 19.7" to 119" gear range, and at 92 cadence low range up to 18.3 kph (11 mph) , and 52 kph (33 mph) in high range. The crank needs to be moved sideways approx 5 mm to miss the BB clamp.
A cheaper crank option is a FSA Gossamer triple with a
153 mm crank ($239 from Bikesmith, with a 30, 39, 53 T chain rings) OR $232 with a 175 mm crank, using the low and middle positions, and possibly a 53 tooth chainring with it teeth machined off as a leg protector and chain retainer.
I have the FSA Gossamer triple on my Silvio V1.0 45 degree seat back, with a 153 mm crank with a 24T round, 39 T Q Ring, and 53 Qring, with a 10 speed 11-34 rear, which gives me a 18.5" to 132" gear range, as this 63 yr old engine is overweight and under-powered, and consumes HUGE quantities of water to run, so 10% grades are at 3.5 kp h
(2.2 mph) at 35 cadence , and 5% declines at 76 kph
(48 mph) at 120 cadence, which I regulary do so I can get up the next hill as far as possible before going at a snail pace!
The drop from midrange to low is large, so I only use low range for grades >5%, and when changing down to low, I need to change up 3 rear gears!
I always had to do one change at a time with my Shimano Ultegra, otherwise the chain would drop off the inside OR get jammed between Low and Mid range.
Should I have had more derailleur tension or a shorter chain as I can just go Large/Large, and Small/Small.
I have added a chain catcher and a bent tent peg to stop this happening.
Have other people with a large drop from Mid to Low had the same problem?