What size of pedal wrench will I need for a Crank Bros Mallet? Is it a 15mm or 9/16?

15mm is 9/16

no it isnt, if i put a 15mm socket on a 9/16 inch bolt it will spin or round off.

9/16" == 14.28mm

now im not sure if pedal wrenches use some sort of wacky math, but i dont think i have ever seen a 15mm socket or wrench fit a 9/16" bolt

I screwed my numbers up. I was thinking 5/8.

15mmmmmmm

I take auto shop in high school, and it seems that 9/16 and 14 mm are compatible.

If it's on a bike, it's metric.

you'd be amazed at how incorrect that is.

Really fore. Every nut and bolt is metric on every new bike I work on. The only standred measurement I deal with are 20", 24", and 26" wheels.

I think that the threads are 9/16, the flats that you actually put the wrench on are 15mm.

you didn't say new bike before, you just said bike.

nuts & bolts may be all be metric now, but there are still other parts of a bike that are standard. steerer tube diameters come to mind, the pitch and width of a chain, axle diameters, pedal spindle diameters, bearing sizes...

I am not sure about the mallet, but Eggbeaters use an allen wrench on the back of the spindle. They don't use a standard pedal wrench.