Triumph Twenty One
... that the 1957 Triumph Twenty One was the first of the Triumph unit construction twin cylinder motorcycles?
... that the 1957 <b id="mwBAQ"><a href="./Triumph_Twenty_One" id="mwBAU" rel="mw:WikiLink" title="Triumph Twenty One">Triumph Twenty One</a></b> was the first of the <a class="mw-redirect" href="./Triumph_Engineering_Co_Ltd" id="mwBAY" rel="mw:WikiLink" title="Triumph Engineering Co Ltd">Triumph</a> <a href="./Unit_construction" id="mwBAc" rel="mw:WikiLink" title="Unit construction">unit construction</a> twin cylinder motorcycles?