Proprietary Rims and Wind Tunnel Objectives

Road trip!This morning, we're packing up a whole lot of wheels to spend some time at wind tunnel camp, at the A2 Wind Tunnel in NC.  We're sending every one of the clincher wheels we currently offer, as well as "canary thunder," the pretty yellow prototype of our proprietary rim design.  The wind tunnel is a significant step for us, in many ways.

We've questioned the validity of how other companies use the wind tunnel, specifically in Mike's post of about a year ago.  You see glamor shots of finished products in the wind tunnel, and you think "why are they sending finished product to the wind tunnel?  If they learn it stinks are they going to scrap the mold?"  We've got our current product line going down there because we want to learn more about it, and we want to be able to benchmark all of it.  We're also sending the wheel that's the de facto aero standard, which will by extension allow us to compare our wheels against pretty much any others out there.  If we find out we've got a clear winner (see below for what that means) on our hands, hooray - we'll have the "finished products in the wind tunnel" photos soon enough.  If we've got a lemon, not just in color but performance, you'll see Tweety Bird mk 2 flapping into that tunnel before long.  This isn't just some exercise in window dressing.  It's important for both you and us to know what kind of performance we're delivering.  If we were going to just pull some fancy performance claims out of our butt, we'd save ourselves the significant cost of this exercise. 

One way in which our wind tunnel aims differ from a lot of other companies is that if other companies produce less than the provable best, walking out without that graph that puts their wheel's line bottom most of all that are out there, they've failed.  It's kind of amazing how many have actually walked out with that golden graph line, but we'll leave that be for now.  In any case, we don't go there needing to stake a claim to that bottom-most line, for a couple of reasons. 

First, aerodynamic competitiveness is a leg of our triangle, but it isn't our triangle.  We also want to avoid going super deep for reasons of weight and practicality.  There's a lot of value in having one really great wheel set, and as we talked about before, we feel that the 50mm neighborhood is a very effective place to be in that regard.  If we're in the aerodynamics class of good wheels that are 10mm deeper, we'll be quite happy with that.  We are also married to the idea of our internal width, as we're absolutely convinced of the benefit, so if the magical aerodynamics fairy was to say "you could show a 3 watt improvement at angles of attack between 5 and 10 degrees if you made the whole thing 6mm skinnier" we'd take a pass.  We need to have good aerodynamics, and if the wind tunnel shows that our design does not have very good aerodynamics, it's back to the drawing board.

Second, it's sort of a crazy game to play in getting to the point where your wheels are demonstrably the aerodynamic best.  There's a cost to benefit thing that goes on, where it becomes more and more likely to geometrically increase your investment to incrementally increase the aerodynamic performance.  How much is a watt worth?  In terms of time, it's worth about 3 seconds over a 40k TT in constant conditions.  In terms of drag, it's worth about 10 grams the way it's figured in the bike world.  In terms of money, for some people it's invaluable, priceless even.  It trumps everything.  For a lot of other people, once you get to where something is quantitatively not giving much, if anything, away from best in aerodynamic class wheels, and taking some back in terms of handling, practicality, weight and build quality, that's a big fat win. 

Developing your own proprietary rim is a challenging and resource intensive proposition. It's taken a lot to get to where we are with this, but at this point the proctor has called "pencils down." We're passing our blue book forward, confident that we've earned a good grade, but we won't know until we know. And if that sounded hopelessly anachronistic to everyone who graduated college after the turn of the millenium, I apologize.