I am having difficulty deciding what to buy to set up a single side drive train. I have been searching the posts and intranet and am still confused. I would prefer the rear to be a 2 X 10 and would like the big ring to be a 53 or 52. The small ring I would like to go as small as possible without having shifting problems. Right now my much heavier tandem (probably 10+ lbs heavier) has an Ultegra triple and I use a 11-27 for all riding including some mnt climbs.

Do you buy a triple rear crank and use the big ring position for the timing chain and then use a single ring crank on the front? (would require the purchase of a 40T ring and a larger granny with the appropriate BCD)

Or would buy double cranks and add the extra timing ring?