Your BB is most likely a 68 since it is a road bike.
Is this your crankset? I have little hands on experience with these but I think that little cap just covers things up. You need to tighten the allen bolt to hold the crank in place. Pics?
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk