We're a 500+lbs tandem team; 40H Dyads worked fine for several thousand miles; then a spoke failure (straight 2.0mm spokes) in the front (captain is much heavier than the stoker). Changed to 48H, and went with Velocity NoBS (same price at Niagara) with Wheelsmith DB14 spokes.

The Dyad front rim was rebuilt with Wheelsmith DB15 spokes, and along the rear wheel is on a mid '90s Trek 720 based commuter.

Hubs are Wheelmaster "tandem" hubs; 135mm rear OLD.