This article first appeared on BikeRadar.
The Giant Propel Disc frameset looks to be production-ready. The Propel Disc's striking stem – which encases the Shimano Dura-Ace Di2 wires and hydraulic lines – is unmarked and alloy, and may or may not be in final form.
While both Sunweb and Giant were tight-lipped about the bike, there are a few discernible points about the bike worth noting.
The original rim-brake Propel features a very slender, hourglass head tube. The Propel Disc has a stouter head tube, presumably for more front end lateral stiffness.
The down tube on the new Propel Disc is massive, as is the junction above the bottom bracket. Hello, frame stiffness.
And the top tube/seat tube junction takes on a larger, curving shape than that of its predecessor.
But perhaps the biggest change aside from the addition of hydraulic discs is the internal integration of shift and cable lines. On Matthews' bike, both the Di2 wires and the hydraulic hoses enter the handlebar just behind the hoods, then run through the stem and into the frame.
BMC's latest Teammachine SLR01 Disc has a somewhat similar design, where the shift and brake lines are secured and covered underneath the the stem before running into the frame. With the Propel Disc, the stem appears to have a top cover, accessible with four bolts. It seems likely that the bottom portion is the structural stem, with the lines sandwiched in between.
An Le, Giant's global marketing director, was vague when asked for details about the new bike.
"Giant is constantly working with our athletes to develop the best products to help them perform at the highest level," Le told BikeRadar. "For this year's Tour de France, we have worked with world-class riders like Team Sunweb's Michael Matthews to engineer and test the next generation aero race bike, with the goal of delivering a clear aero advantage in the sprints."
BikeRadar photographed Matthews' bike two days before the start of the Tour de France, just before Matthews and his teammates went out for a training ride. Mechanics had not yet installed handlebar tape, as Matthews wanted to make sure the levers and sprint shifters were positioned just right. And mechanics had not yet installed a power meter.
Stay tuned for more details as they become available.