Australian sprinter Michael Matthews has been seen testing a new Giant Propel Disc at the Tour de France.

The original Giant Propel was launched back in 2013 and currently represents one of the older aero bike designs being used in the pro peloton. However, it appears the launch of a new updated disc brake equipped version is imminent.

The Giant Propel Disc is equipped with flat-mount disc brakes and leverless thru-axles

The biggest difference from the old Propel is the inclusion of disc brakes, with Matthews’s bike equipped with the new Shimano Dura-Ace R9170 Di2 groupset.

The new Giant Propel Disc belonging to Michael Matthews

Cockpit integration has been increased significantly, with no visible cables around the bar and stem. Rather than an integrated bar and stem, single piece, Giant has opted for a potentially better solution.

A prototype Garmin mount

The stem and bar are separate components, which should mean it is far easier for riders to get their preferred stem length and bar width. With one-piece aero bars, this can be difficult.

>>> Review of the Giant Propel 0

Giant Propel Disc features a new integrated cockpit with a separate aero bar and stem

It may look similar, but the shapes of the tubes on the new Propel Disc are also quite different. The new design features wider tubes and the down tube in particular has a Kamm tail profile, rather than the aerofoil cross-section of the older design. To see how it compares, click here to view the original Giant Propel.

Tube shapes have changed and the headtube appears shorter on the new Giant Propel Disc

The inclusion of discs also appears to allow for much-improved tyre clearance. Michael Matthews’s Sunweb bike was fitted with 25mm Vittoria tyres and there was plenty of room for something wider. The Propel Disc is also making use of leverless thru-axles, something which has the potential save a couple of watts.

Turning the bars results in a small flap opening. Perhaps similar to the Trek Madone Vector wings

Another significant change is the head tube, which appears to be shorter on the new Propel disc, when compared to the old version.

Despite the changes, the new bike certainly retains the DNA of the original with features retained, such as the integrated seatpost.