High-end cycling shoes usually consists of a nominally flat carbon sole plate onto which is bonded a complete upper that fully wraps the top and bottom of the foot.
Australian shoemaker Bont, however, opts for a handbuilt monocoque layout whereby the microfibre (or optional real leather) upper is bonded around the periphery to a bathtub-shaped carbon lower half.
The result is a shoe that's stiffer and noticeably more efficient at transferring power (yes, really) than nearly any other shoe we've sampled and yet also one of the lightest.
The bathtub-shaped sole offers other advantages, too. In addition to being much more rigid than a flat plate of equivalent thickness, it lends more support – especially in the arch – by enveloping your foot on all sides.
Since the stiffness comes about from a structurally superior U-shaped cross-section, stack height is dropped to an ultra-low sub-4mm – we actually had to lower saddles on test bikes by several millimeters to achieve the same leg extensions.
Moreover, the monocoque layout omits much of the material redundancy of conventional shoe construction. Even with the monstrous stiffness, a pair of size 41 testers weighs just 503g.
All of that stiffness would do little good if your feet were allowed to swim around, though, and thankfully the a-ones do an excellent job in that department as well. Ample footholding power is provided by the broad ratcheting main strap that pulls your foot down and back, a pair of large Velcro forefoot straps and a deep heel cup.
Feel free to tighten the strap down an extra notch, too. The perforated tongue is generously padded with high-density, true memory foam (as opposed to the 'memory foam' used by some other shoes we've tried) that keeps the strap from cutting into your instep.
Feeling the heat
Though light, stiff and supportive straight out of the box, the a-one's ace in the hole is its fully heat mouldable upper and lower, which add comfort and also prevent the numbness and hot spots that can sometimes accompany shoes that are too stiff.
Toast them up in a 70°C (160°F) oven for 20 minutes, let them cool just slightly then tighten the straps around your foot. Once cool, they're literally wrapped around your own anatomy and with a little bit of extra work, the shoes will even accommodate left/right differences and anomalies like Tailor's bunions provided they're not too severe.
As further insurance to a proper fit, the process can be repeated ad infinitum until they feel right and Bont also offers narrow, standard and wide widths. In the most extreme cases, Bont can also do a fully custom pair.
Getting the fit dialled in is vital to gaining the most out of the a-one as while it's one of the shoe's most appealing qualities, it can also elicit the exact opposite experience if done incorrectly.
Our first rides weren't all that comfortable as the composite cradle around the forefoot and arch can feel awkward compared to conventional shoes and downright painful over time if the shape differs significantly from your own foot. Once moulded, though, the a-ones feel much more natural with no hot spots to speak of and a snug, sock-like fit throughout.
Form vs function
All that being said, the a-one won't suit everyone. Even with their premium price tag, the finish work betrays their one-at-a-time handbuilt construction with the occasional slight gap and raw-looking cut lines plus visible glue at some of the seams. From an aesthetic standpoint, Bont offer the a-one in a generous octet of colours but even so, the design is decidedly love-it-or-hate-it depending on your perspective.
Breathability is surprisingly good in spite of the microfibre's shiny look and the tiny-looking perforations around the edges of the upper – our feet actually got cold when riding in 10°C (50°F) temps – but ventilation leaves a little to be desired compared to shoes with more open mesh and scooping sole vents. Bont's latest generation adds a protective plastic toe cap, though, with intake holes placed right up front for more of a wind-in-your-toes feeling.
Sizing is a bit strange, too, with printed sizes running nearly 1½-2 sizes larger than major makes such as Sidi, Specialized and Shimano. Best to try before you buy or take Bont's suggestion and send them a tracing of your foot as per the instructions on their website to ensure the proper size.
Functionally speaking, the Bont a-ones are a compelling choice of top-end, premium footwear. They're insanely stiff with unquestionably pure transfer of pedalling force, offer an excellent fit once properly moulded, and are very light with excellent breathability.
Not surprisingly, they've therefore been the choice of a number of pro riders such as Bradley Wiggins, Roger Hammond, Michael Rogers and Hayden Roulston, and now the entire Cervélo TestTeam for 2010.
However, average consumers shelling out that kind of money are invariably going to expect a more finished-looking final product. Function may be the key to performance but form is still important, too.