There are two sensible ways of measuring the width of drop handlebars - from the centre of the bars on each drop, or from the outer edge of the bars at the drops. Either would do, but they are not the same. Wouldn't life be easier if all manufacturers could agree on the same way of measuring them? I wanted to replace some bars that were clearly marked as '42cm', and ordered a 42cm set from Deda. On arrival, the Deda set is approximately 2cm narrower than the old ones, because Deda measure edge to edge, and others centre-to-centre. That is my moan. Pay careful attention when buying these things.