The Bont Zero Plus shoes, which we first took a look at last January, are a reworked version of the original Zero shoes. The 'Plus' version has the same full fastener cover design as the original, but while that had laces, the Zero+ has the Atop ratchet system that Bont uses in its Vaypor+ shoes.
This switch to a dial system means there's less bulk underneath the cover, creating a smoother line to the shoe, a shape that Bont also claims is more aerodynamic than the original, though it has still retained the bathtub-shaped sole.
We've tried pretty much everybody's custom-fit systems but Bont's is by far the most extreme. The amount of shaping you can do to the shoe after heating makes for a truly personalised fit.
That said, earlier Bonts didn't always agree with some of our testers' feet, their cramped toe-box making them difficult to wear for long periods. Bont has now increased toe-box volume and the move away from the stiff woven fibre upper of the previous Zero also adds plushness. The golf ball-patterned DuroLite upper is more compliant and flexible, adding even more comfort to a shoe that wasn't renowned for it.
The new Zero+ shoes are a joy to use. No matter how hard we pushed and pulled we couldn't discern even the slightest flex in them. Having your foot in the right position feels powerful and efficient, and gives you the sense that every ounce of your effort is being used to propel you forward faster.
Ventilation has never been a major factor in Bont's designs. The one-piece uni-directional carbon sole has no vents, while the upper just has minimal mesh vents in the toe bumper and pin-hole vents in the toe-box. In spite of that we've been wearing them from summer and into the winter and haven't found them lacking.
We've no reason to doubt Bont's claims about the aerodynamic advantages of these. Time triallists have long known that a covered shoe is faster. They're among the lightest shoes we've tested too; our size 45s weigh 502g, and they're also the stiffest and the most tunable.
The only downside is that the carbon sole can get scuffed fairly quickly. That, and the prohibitively high price.