Gear levers & shifters
Shimano Dura-Ace Di2 9070 offers swift, faultless shifting and a few extra features that make it an even better proposition than the initial version.
Retroshift is a combined braking and shifting system straight outta Portland in Oregon in the U.S of A and touted as an alternative to dragging your expensive mechanical STI/Ergo/DoubleTap levers around dirty, muddy, crash-prone cyclo-cross races, although obviously their use can be extended to be capable on tourers, commuters, expedition bikes, winter bikes, or any bike that might utilise what some would call a brifter.
If you've got a flat barred bike and you want to run a 10-speed cassette you'd be forgiven for thinking that your only options are Shimano's R770 shfiters or the swish, but even more expensive, SRAM DoubleTap units. You'd be wrong though: You may not have heard of Microshift but that's no reason not to give them some serious consideration for space on your bars, because they perform really well for less than half the price of R770s, and a third the cost of DoubleTap.