Sorry to sound like the high school teacher saying "narrow it down," but I think the subject really is a bit broad.
Yes, I suppose I was just a bit too broad. I guess what I was really asking is when pro racers started using aluminum stems/bars and why did they stic k to steel for so long (through the 1950s, as it has been suggested.) Sorry for the broad topic, but I think Tom and others have successfully ans wered my question. Thanks everyone!
--Kirke Campbell
Houston, Tx