Designing stuff

[Marmoot]

Precisely, the 4 spoke can be designed to achieve the required stiffness but it'd be heavier than the 3 or 5 spoke, hence obsolete. Not that I've done the calcs on this myself, makes sense thinkin' about it conceptually but everything can always be proven wrong.

I think you guys are absolutely right. I missed a detail in previous statements.

4-spoke is workable, as long as they are put at an angle so that they are not placed as a radius (i.e., a straight line from center of the circle to the contact point between tyre and road).

Cheers.

[avgas]

Also no one has pointed out that 3 spoke wheels are easier to inject mould. More surface area leads + more volume = less errors

[erik]

Precisely, the 4 spoke can be designed to achieve the required stiffness but it'd be heavier than the 3 or 5 spoke, hence obsolete. Not that I've done the calcs on this myself, makes sense thinkin' about it conceptually but everything can always be proven wrong.

How can you assume it'll be heavier?
If you use 4 spokes, each individual spoke could be lighter than the individual spokes in a 3 spoke wheel. Plus the rim might be able to be lighter as there would be a smaller span between the spokes.
I don't think it's possible to say one would be lighter than the other without actually designing them and going through the calcs.

4-spoke is workable, as long as they are put at an angle so that they are not placed as a radius (i.e., a straight line from center of the circle to the contact point between tyre and road).

With wire-spoked wheels, the spokes need to be at an angle. If they were at a radius, they could not offer any significant resistance to axial torque (ie from accelerating or braking) until the hub of the wheel had rotated a certain amount, effectively putting the spokes at an angle. I'm not sure how to explain this other than to give an example. Take a piece of string drawn tight between two points so that the string is horizontal. If you try to make the centre of the string deflect downwards, it will take very little force at first, but as the deflection (and hence angle of the string from horizontal) increases, the required force increases (exponentially, I guess?).

However, with cast alloy wheels (which is what I'm assuming we're talking about here) the spokes are thick and can therefore offer resistance to bending at the hub of the wheel, even if they're placed as a radius.
They don't need to be placed at an angle.

Thinking about it, even though cast spokes do not need to be at an angle, I guess they might benefit from it in the same way (to a lesser extent) that wire spoked wheels do. But having the spokes at an angle would also make them longer, which may make them heavier.

However, none of this suggests a 4 spoke wheel is at any disadvantage when compared to wheels with other numbers of spokes.

[Marmoot]

However, none of this suggests a 4 spoke wheel is at any disadvantage when compared to wheels with other numbers of spokes.

well...one can always argue that "4-spoke is ghey" without the need for specifics