Originally Posted by
Retro Grouch
Lots of wheels have been built with the left and right hub flanges the same rather than a mirror image of one another. I suspect that made it easier to insert the spokes into the flanges.
Not quite, that's the same effort either way. The reason for non-mirrored wheels is the process of production buiding, wherein all the spokes are loaded into the hub, which is then mounted into a wheel lacing fixture or machine. The spokes are brought to the rim in crossed and the nipples attached.
There ar two ways to do this - lace the upper flange first, then flip the wheel and lace the other -- or -- lace the lower flange, then the upper. The second saves the time to flip the wheel and is faster by that amount, but it' hard to teach hands to work in the opposite (mirrored) direction, so both flanges are the same. To give you a sense of how important the few seconds to flip the wheel are, a decent worker can lace about 60 wheels per hour, so losing 6 seconds to flip the wheel is a lost 10% of production capacity.