Originally Posted by
topflightpro
OP, at you weight, you could easily go 20h front and 24h rear. 32 would be overkill, unless your goal is to build an incredibly solid and overbuilt wheelset. And yes, they will be unnecessarily heavy and will not be terribly aerodynamic.
That's not really true.
First, define what you mean by "heavy" - spinning weight and how far out from the hub centre (the further out the weight is, the more influence on acceleration as well as the "feel" of the wheel it has). A good number of "aero" wheels place a lot of the weight peripherally (hence using carbon rather than alloy) ... a "heavier" wheel with the weight predominantly at the centre will often out-accelerate and feel "lighter" than a low spoke-count aero wheel, especially given that the rim often needs to be beefed up to account for the generally higher spoke tensions needed as spoke count falls and are in consequence heavier - the weight losses from reducing the spoke count are not necessarily compensated as a result..
As for aero, yes, more spokes do create more turbulence in still air - but by the time you take real world, relatively chaotic arirflow into account, especially around the back wheel, the effects at relatively low speeds (30-35kmh) are not as great as you might imagine. Wheels account for roughly 3% of the aerodynamic drag of the rider / bike complex so practicality can sometimes score over aerodynamics. The best wheels are real-world as well as wind-tunnel tested and the best wheels for the job are not necessarily the lightest / most aero / have the fewest spokes.
That's the skill of a wheel builder - I can teach almost anyone to build a serviceable, durable, 32 or 36H tangentailly laced wheel in a couple of days - the "black art" is in matching the components to the rider's needs and making the wheel that is tuned to them, specifically.
That's definitely, definitely, not to say - "handbuilt good, factory-built bad" or anything like it - but it should always be taken into account that a factory built wheel is always a series of compromises as the designer has to assume rider weight between around 50kgs and 110 kgs, has to assume very mixed surfaces, has to assume a wide variety of use conditions and a wide spread of inclination to maintain the wheels ... so in many cases, a built-for-the-job solution is better. A well designed and built set of radial and cross 32s might well out-perform a super whizz-bang aero set of wheels for a lighter rider who mostly rides at around 30 - 35kph, for instance.