Shimano dura ace di2 r9150 braze on front mechthe dura ace 9150 front derailleur delivers unmatched shift quality for quick and smooth performance even under high pedalling torque combined with shimanos synchro shift customisable programming dura ace di2 delivers a level of intuitive shift performance never before seen top gear teeth46 55t chainstay angle61 66 chain line435 ergonomic shifting operation without stress shimano synchronised shift race endurance for less damage in crash