Originally Posted by bentrox!
My SWB is set up with a 30-42-52 Ultegra road bike chainwheel and front derailleur paired with an 11-32 XTR mountain bike cassette and rear derailleur. If you want maximum speed on those flats you'll love the 52-11 combo (you may spin out with a 46, especially on descents.) At the other end, 30-32 means you can spin up the steepest hill, albeit very slowly. I rarely use the granny, though, but will drop down into the 42 for some long climbs. Cross-chaining conflicts don't seem to apply much to recumbents because of the unusually long distance between front and rear derailleur, so sometimes for those short rollers I'll just stay in the big ring but downshift to the big cog - usually a no-no. I love the Ultegra-XTR combination with Rapidfire shifters. I've never had a problem with shifting at either end.
The 10 tooth gaps are easy shifts, particularly aiding the downshift to the middle chainring.
46-36-26 is a Mt. bike tripple. Mountain bikes shift more often benefitting more from smaller chainring size jumps, don't need the higher ratio afforded with a 52T, and benefit from more ground clearance and lighter weight from smaller rings.
52-42-30 is a road triple, generally on a 130 bcd bolt pattern, using the higher gear ratio's possible with the 52T. The 10T drop makes the difficult downshift to the middle ring easier. The drop to/from the 30T is less frequent, so a rough shift here is less critical, and the drop to the inner ring is less difficult than the middle anyway since the chain is less likely to be overthrown.
48-38-28 is a compromise between the two.
You won't go to the granny that often, the 42/52 big pair is closer percentagewise than the alternatives you posted, and you are likely to need the higher ratios on a bent, particulary in the riding styles you identified. Go with that or something cloes first.