I’m going to be honest, I don’t think my WR56 wheels are the stiffest in the world. Most people measure stiffness by looking at rim edge to rim edge, and of course, a super deep carbon rim is going to be way stiffer end to end than a shallow alloy rim. There’s more material across the same distance.

However, few people ever measures stiffness from the spoke hole to the tire bead. A 25mm deep rim is going to have to deal with less leverage than a 56mm deep rim. I think that is the “X factor” that separates amazing carbon wheels from meh ones. Corima, for example, has a torsion bar in all of their rims to reduce flex in that area.

I enjoy climbing way more on my cheapo alloy wheelset. My hypothesis is that it’s because there is less spoke hole to tire bead flex. I assume this is what you’re talking about, and not the amount of flex at the “brake track” which is almost purely dictated by spoke stiffness.

I highly recommend getting 28-32 Race or CX-Sprint spokes for track. I get a considerable amount of brake rub from my 24 CX-rays (on my WR56) and I weigh 140ish lbs.

I’m fairly uneducated about this topic and didn’t think rim stiffness mattered until I bought these wheels. So ofc I’m open to having my mind changed.