The clamp area is wide enough for most 31.8 stems, then the diameter drops to the usual size quickly. They look a bit rubbish but I can't see how that makes them less stiff than the standard alu ones? I think their idea was to make them OS to fit more stems, not to make them stiffer.
(One of) the stiffest combo I've ever handled is Nitto chromo 34cm in a pro 7s stem (with shims from 25.4-31.8) at that point you start getting into how flexible the fork steerer is.
The clamp area is wide enough for most 31.8 stems, then the diameter drops to the usual size quickly. They look a bit rubbish but I can't see how that makes them less stiff than the standard alu ones? I think their idea was to make them OS to fit more stems, not to make them stiffer.
(One of) the stiffest combo I've ever handled is Nitto chromo 34cm in a pro 7s stem (with shims from 25.4-31.8) at that point you start getting into how flexible the fork steerer is.
Anyhow, complete digression from the OP.