Chain ring

asm You'll want a 144 BCD chainring then. (Am i right?)

If it's the crank spider that had 2 chainrings on it, then i doubt it'll be a 75. I thought being track specific they'd only accommodate one chainring. But i've been wrong in the past! (Quite a lot actually)

Don't know if they have a 144 BCD but Sugino definitely do the 75 as a double crank as well, I bought one accidentally a while back.