[OceanMan]

I have a hard blade hyper from leaderfin and a kershkov monofin (hyperfin like).
They don't bend like Ben's monofin. No v-bend and no footpocket bend even with kick&glide style.

I totally agree with Trux when he says that a monofin should not bend this way for optimal propulsion.

I think it really depends on the design of the fin. For sure, a wide and large blade can only make things worse.

What is weird is that the same fin can either show bad bending or not.
I know glide fins have the problem but recently a guy from my club bought one and the fin has no bad bending.
All hyperfins don't bend the way ben's one does either. I have many videos of freedivers using hyperfins and hyperfins-like monofins (including Pedersen and Stig) and 90% of the fins show no footpocket bending and no v-bending at all.
Why ?