Originally Posted by
tradtimbo
radial is fine on the front for modern hubs and spokes. Radial pattern puts more stress on the outer edge of the hub flange than a cross pattern, thus it makes a bit weaker. radial pattern on the rear is not a good choice because of the torsion force you place on the wheel as you accelerate. The benefit of radial pattern in the front is shorter spokes, thus a lighter wheel (we're not talking much here).
go with 3 cross.
It's all fairly negligeble. aerodynamics are improved if the built wheel has all the spoke heads facing out (so the wheel has a front profile that's just a hair narrower than a wheel with alternating in/out facing heads) but to take full advantage of the lateral stiffness lacing radially provides, you want the spoke heads to face in to increase the width of the 'stance' of the spokes (like spreading your legs to improve side to side balance.) There is still some lateral strength benefit because of the shorter spokes.
Buying high flange hubs also adds lateral rigidity, but it costs you more in weight.
edit: mixed up heads and nipples. All corrected