DUO StemsRenthal's revolutionary DUO stem combines high strength with ultra low weight. The stem is horizontally divided down the centre which allows it to be CNC machined in two pieces. This method allows unrestricted access to the core of the stem which enables weight to be reduced to the absolute minimum without compromising strength. In addition this provides an uninterrupted U shape clamping area, which eliminates the stress risers found on most other clamps which can lead to handlebar failure. Two reach versions available: 50mm & 40mm.Features- CNC Machined from 6082 T6 aluminium alloy - Split stem design for maximum weight reduction - U shape clamping area, eliminates traditional stress risers for the handlebar.- Patent Pending50mm:- 137g (including bolts) - 31.8mm handlebar diameter - 50mm offset/10 degree rise/40mm stack height40mm:- 124g (including bolts) - 31.8mm handlebar diameter - 40mm offset/10 degree rise/40mm stack height