Medium profile rims - why bother?

kenbaxter

Looking for new race wheels for this year. Was looking at Ksyriums/Eurus/Shamal vs deep section Cosmic Carbone/Planet X etc.

Opinion seems to be that semi aero wheels have no aero effect until they reach about 40mm. As such what is the point of a semi aero wheel (Eurs/Shamals are 28mm, and I think Ksyriums are similar)? Does it make the rim stronger? Just trying to establish what are the real benefits here or should it be a choice of deep rim (Cosmics) vs normal rim (e.g Neutrons) and just include the Eurus etc in the "normal rim" category.

Thanks.

redddraggon

The deeper the rims the stiffer they will be (generally).

I went for neutron ultras over Eurus wheels personally.

andrew_s

stiffer in the vertical plane means they will cope with bigger gaps between the spokes

Monty Dog

And fewer spokes or long unsupported section of rim means that re-trueing can be a right royal pain to rectify.

JWSurrey

What Monty said....
If my memory serves me correct, the Campag. wheel literature even states that you should not tinker with the spokes as they're under high tensile loads.
The low spoke count mid section Campag. wheels (Ventos) I ran before stayed true to the end, with low spoke counts and clearly a stiff rim.
I believe a snapped spoke on a low spoke count wheel will also be more drastic than one on a high spoke count wheel - such as one with a traditional rim section.

My 32H handbuilts ride smoother with the same (or slightly lower) overall weight.
My personal choice from your list would be the Neutrons, as I've been enviously eyeing them up for some time - though I can't find a good excuse to buy a pair!

redddraggon

Neutrons look good but then so do most campag wheels.