Steel framed road bikes should have them to give any water ingress a chance to get out...or dry out, but it's not critical. From what I understand bottom bracket shells typically came without cutouts/drain holes, so it would be up to the frame builder to add them - usually in a creative sort of way as this thread illustrates. So, production frames were probably less likely to have them as it wouldn't be cost effective cutting holes in hundreds of bottom bracket shells.


Kumo track bike made in Canberra, Australia.