Bouwmeester's Hors Categorie wheels provide a tangible advantage when going uphill, even for riders who aren't slight of build or have a sky-high VO2 max and Grant Tour-winning power-to-weight ratios.
At an actual weight of just 1,020g for the pair, the effect on climbing speed is about what one would expect. We beat a personal best on a favourite 10km-long climb in the outskirts of Adelaide, Australia by nearly three minutes – in less than ideal conditions. [Calculations of expected time losses based on weight reduction and aerodynamics gains using Steve Hed's simulation program predict time savings closer to one minute, not three. Les must have had a good day - Ed.]
Steep sections feel a little flatter, the wheels are rockets to accelerate on more level stretches, and the shallow rims are only barely affected by stiff crosswinds. Reasonably stiff construction keeps them from feeling too noodly.
Everything about the Hors Categorie's build is aimed at reducing weight. The barely-there carbon fibre tubular rims are just 20mm deep, the bladed spoke counts are a minimal 20/24 front/rear, and Bouwmeester's proprietary alloy hubs supposedly weigh just 62g for the front and 205g for the rear.
They come complete with silicon nitride hybrid ceramic cartridge bearings pushed all the way out to the edges of the shell, interchangeable alloy freehub bodies, and oversized aluminum axles.
The high-quality hybrid ceramic ingredients and precision bearing seat machining yield some of the smoothest and fastest rolling we've experienced, though some of that can undoubtedly be attributed to the fact that Bouwmeester add no dust shields or seals to supplement the cartridges.
Though we didn't experience any bearing issues in our dry Australian test grounds, regular maintenance is recommended and riders who foresee using these in wetter weather will want to take the minimal protection into account.
Not everyone will be able to enjoy the Hors Categories' feathery ascending performance. Bouwmeester assign a 75kg (165lb) rider weight limit to this dedicated climbing model and while an extra kilo or two might not matter much, riders pushing 80kg and over are certainly ruled out.
In addition, the Hors Categorie is available solely for use with tubulars so these should be restricted to racing only lest you shoe the rims with more durable tyres or are willing to carry a spare.
Light or not, the Bouwmeester Hors Categorie wheels aren't going to turn anyone into Cadel Evans, Alberto Contador or Andy Schleck – you've still got to train, after all.
But they still provide a tantalising complete climbing package that can cleave minutes from your ascents, even if the engine driving it isn't quite what it needs to be in order to be called a true mountain goat.
RRP for the Hors Categorie wheelset is AU$2,599 – there's no official UK or US RRP. Prices listed in this review are currency conversions that were correct at the time of publication.