I had a 40 hole 4x rear Dyad on a Velocity 9spd free hub and a 36h 4x on velocity hub for the front. ran over a curb straight on while loaded doing less than 5 mph/ 8kph and carried on. After something like 600 miles though the rear rim spread apart to the point that it would no longer pass through the chainstays and now about 1000 miles later the same is happening with the front rim. I was told this was due to riding with my schwalbe Marathon XRs at maximum pressure (85 psi). The impact supposedly amplified the pressure enough to cause a blip in the rim on both sides that gradually spreads 'til the rim is no longer usable. Can't really ride with lower pressure though because of concerns of hitting the rim in a similar impact so FWIW I'm not terribly impressed with Dyads. Sure, we don't run over curbs every day but doing so shouldn't derail your bloody tour for a week while you wait for replacements.