Like a lot of the very latest carbon wheels, Vision have plumped for wider rims. They have used computational fluid dynamics and wind tunnel testing to come up with a much more rounded shape than before, with similarities to Zipp's Firecrest 303 and Enve's Smart design.
The new hub features a big 17mm diameter axle and full ceramic bearings. The front has 18 bladed aero spokes laced radially, the rear has seven radial spokes on the non-drive-side and 14 laced two-cross on the drive-side.
Their 1,612g weight (727g front, 885g rear) is pretty similar to that of the Zipp 303s, which weigh 1,578g but are significantly more expensive at £2,300. With similar all-carbon construction, profiles and rim depths - 40mm for Metron, 45mm for Zipp - it's the Zipps that the Metrons will inevitably be compared to.
The Metrons run exceptionally smoothly, and we'd go as far as to say that they spin even more freely than the Firecrests. The Metrons were influenced a little more than the Zipps in blustery conditions, but it's a feeling of pressure at the handlebar more than anything, and it's easy to hold your line by applying a little countersteer. Thankfully this never appeared as the sort of violent jolt that we've occasionally experienced on budget aero wheels based around simpler V-shaped rims.
The wheels have been put through the grinder during several hundred miles of all-weather riding. Under hard sprints they remained rock solid, and we haven't heard any brake rub or been able to induce any flex even when pushing them really hard. Braking is sharp and positive without feeling overly grabby, and the rims aren't showing any signs of wear or scoring either. In fact, fast brake pad wear is the only sign of their usage.
We've been seriously impressed by the 40s. While we believe the 303 Firecrest is still the king of the carbon clinchers, the Metrons are within a whisker of their performance yet are priced at £800 less, which is very impressive for a wheel that's still assembled by hand in Italy.
The Metrons come complete with wheel bags, valve extenders, carbon-specific pads and quick releases with carbon handles. The result is a genuine high-performance wheelset at a great value price.