I’ve had mine since March 2014 and just swapped out cassette, chainrings and chain. All consumable parts. Everytning has worked perfect from day one however I will be upgrading to some new parts just for the technology upgrade. New battery and Bluetooth DFly for using the E-tube app. on my iPad. May even get 8050 shifters for the buttons in the hoods. Longevity is yet to be seen I would think.