'Tis the season for manufacturers to sneak a sneak peek at their new bikes ahead of the official launch of the Tour de France. Usually in the pre-Tour races, we see a few active pros riding their new bikes, like the Canyon Ultimate and Trek Madone. However, it is more rare to see bold camouflage like Pinarello's new Bolide, which acknowledges the new bike's arrival but avoids making people understand its shape.

More unusual than I can remember is the sighting of a new bike under a former pro while out and about. Admittedly, this former pro is Tony Martin, and "out and about" is my way of saying "insane sportive training," but it's still unusual.

So far we only have a snapshot from Instagram, but when you combine the two with the new list of UCI-approved frames (which coincidentally features the new Propel), you don't have to be Sherlock Holmes to deduce that this is probably it.

If this is indeed the new Propel, then Giant's design desk has changed significantly. The old Propel was in the classic mold of an aerobike, all deep sections, integrated at every corner, but with a weight penalty. This new model seems to be aiming for the all-around race bike angle.

The tube shape was clearly dainty, especially the seat tube. Not only is it less deep, but it appears that the original seat post has been replaced with an integrated seat mast. The seatstays are also thinner and are joined straight to the seatpost with a small triangular filler at the joint, eliminating the near wishbone setup.

The top tube has a narrower vertical axis and is now properly level, with no upward bending at the junction. The down tube is shallower and more in keeping with the theme, but not drastically changed. The base is connected to the bottom bracket, which, at least by the looks of it, is also smaller.

The second Instagram post offers a glimpse of the cockpit. The bar has standard clamps, and at least the top cap is visible.

Martin also appears to have been trying out a new set of wheels. There are no official brand markings, and there appears to be a handwritten note on the sidewall of the rim.

As with most leaked bikes (intentional or otherwise), official information on the intended release date is lacking. Our guess is that, given the timing, Giant will tie it to the Tour.