Q:

How many spokes for a single speed road bike?

I want to buy a handbuilt wheelset from a local bike shop and I am in front of the decision of how many spokes I want to put on front and rear wheel.
The application of the wheelset is a singlespeed bike, to be used mostly on paved road (I have another wheelset for gravel) by an 80Kg rider. The rear wheel is going to be built with a track hub with a White Industries freewheel.
I was thinking of lacing 32/32, but then I read the following on Sheldon Brown:

If you have the same number of spokes front and rear, either the front wheel is heavier than it needs to be, or the rear wheel is weaker than it should be.

Does this still hold on modern rims/hubs? What's the number of spokes recommended for my setup? Do all combination make sense or only some of them? For instance, is 28 front/32 rear ok?

A:

If you have the same number of spokes front and rear, either the front wheel is heavier than it needs to be, or the rear wheel is weaker than it should be.

In general, that's still true.
The rear wheel generally is subjected to much greater stresses than the front wheel - the rear wheel normally supports about 60% of the combined weight of the rider/bicycle combination along with all of the power transmission.
The only time a front wheel is normally subject to greater stresses than the rear wheel is under braking, where the front wheel takes most of the stress.  But braking is normally a fairly smooth force that is less stressful than bearing weight over bumps or the peak stresses of transmitting power from the pedals to the road.  And for rim brakes at least, the stress on the wheel is a lot less as there's no torque on the hub and spokes like there is on the rear wheel, where power is transmitted from the chain to the road via torque through the hub and spokes.
Note that was likely written before disk brakes.  Disk brakes change things because the braking force has to be transmitted through the hub and spokes to the rim.  So you don't want to to have a 32-spoke 3-cross rear wheel with a 20 or 24-spoke radially-laced front disk brake wheel (pretty much a normal configuration for my rim-brake road bike 32/3x rear, 20-24/radial front).
But I suspect with a front disk brake, a 32-spoke 3-cross rear paired with a 28-spoke 2-cross front would be fine.
Overall, though, having a few extra spokes on the front wheel isn't going to matter much.  If I could save $50 or more by buying an off-the-shelf 32/32 over a custom-built 32/24, I'd personally use the money on something more useful than a few less ounces of spokes.

