By Martyn Herman RIO DE JANEIRO (Reuters) - The two fastest women's track cycling pursuit teams locked horns for gold at the Olympics on Saturday but the expected close battle ended in a romp for Britain as they crushed their American rivals in another world record. After trailing early on the quartet of Laura Trott, Katie Archibald, Elinor Barker and Joanna Rowsell-Shand cranked up the pace to devastating effect, winning in 4:10.236 -- nearly two seconds quicker than the world record they set in the heats. More...