Old fashioned spoke counts were based on weak old fashioned spokes, and people have raced tandems on 16-spoke wheels (Shamals and Shimano Sweet-16s), both of which have features (deep rims on the Shamal, heavily offset spoke anchorages on the Sweet-16) which make them stiffer but not stronger per spoke than yours. I expect the wheels will be OK for strength, but 36-spokes rear with dish might be a bit marginal on axial stiffness if you're loading the bike up. Other tandemists will probably weigh in with opinions; as you can see from my tandem build thread, mine has yet to reach the point of actually being ridden :-)
I know it's getting to be a bit of a broken record, but for a tandem DT Alpine III (or equivalent) really is worth the extra over other spokes. Cheapest 3 ounces of insurance you'll ever buy.
Old fashioned spoke counts were based on weak old fashioned spokes, and people have raced tandems on 16-spoke wheels (Shamals and Shimano Sweet-16s), both of which have features (deep rims on the Shamal, heavily offset spoke anchorages on the Sweet-16) which make them stiffer but not stronger per spoke than yours. I expect the wheels will be OK for strength, but 36-spokes rear with dish might be a bit marginal on axial stiffness if you're loading the bike up. Other tandemists will probably weigh in with opinions; as you can see from my tandem build thread, mine has yet to reach the point of actually being ridden :-)
I know it's getting to be a bit of a broken record, but for a tandem DT Alpine III (or equivalent) really is worth the extra over other spokes. Cheapest 3 ounces of insurance you'll ever buy.