OH you want to use that clamp on your road bike right?
No those shifters are self contained and lock to the base by 4 little numbs that fit into the base. If you had a set of these thumbshifter there no reason you can't use them on your road bike assuming the number of speeds match.
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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