Yuni bearing maincap caps?

are these made of steel or aluminum? just wanna know… i just had a great idea for a frame… but no one can know what yet…

They are steel. Whats your idea??

not telling 'til its finished.
work starts this weekend.
but its either going to be a muni or trials frame.

also:
does anyone know what kind of pipe i need for a seatpost holder?

oh wait… i might have some. leftover from the giraffe project…