Choosing an extension length is easy if you start from your existing bike set up. Decide if you need the same or a slightly different amount of reach and then measure from the saddle tip forward on your new frame to work out the length required.

Handlebar width and shape is more of a personal 'feel'. The modern super shallow bar shape allows a lower extension clamping height while still leaving the drops within reach.

FaLang translation system by Faboba