Earlier this year, Null Winds introduced their upper wheel fairing concept to block wind from the top section of spokes that typically push into the wind, creating multiples of drag compared to other parts of the bike. Aesthetically that device left quite a bit to be desired, but it looks like their new AeroTaper spoke could be just the solution.
The design works like this: A round spoke profile is used closer to the hub where the spoke is moving slower in relation to the wind. Because they’re round, they don’t impose as much penalty in a cross wind and have minimal aerodynamic penalty for the headwind. Closer to the rim, where the spokes are moving relatively faster, it flattens out to create an aero shape where they need to slice through a head wind better. Thus, an optimized cross sectional profile.
It’s not dissimilar to the idea of deep section aero rims, and you’ve got plenty of choices in rim depths to suit conditions. Likewise, Null Winds founder Garth Magee says they’ll have different taper depths to suit varying degrees of cross winds. No, you won’t rebuild your wheel every time. Rather, you’ll have a rim that you really like and have several different wheels built with different AeroTaper spokes and choose according to the day’s conditions.