what is the width of an american bb from crank side to crank side?

I think its 68mm but there is another of 73mm

Measure the shell. If you don't have a way to measure millimeters, the conversion is:

68mm = 2.667" (just under 2 11/16")
73mm = 2.874" (call it 2 7/8")

My cruiser frames look to be 68mm.

2.625"(66.7mm) for an american bb shell

i think he after the width not the diameter

yeah im making a bb decals for a vbmxer and its for the bottom of the braket and was sending it out today but didnt know the width of the bb shell

That is the width.

i'm not going out to the shed now it's quarter past 4 in the morning here and i'm about to go to bed
'night all