Thanks to the UCI recognising the sport, gravel racing is huge these days, and now, brands are scrambling to create bikes and components to help racers gain the edge against their rivals. That means big tyres and aero features, and that’s exactly what Fulcrum has done with its latest Sharq GR and Sonic GR wheelsets. Here’s everything you need to know.
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There are other ways in which gravel is gaining performance, and that’s by pinching technologies from mountain biking, like suspension forks. But for Fulcrum, the brand has gifted its new Sharq and Sonic GR rims 30mm internal widths, a measurement that’s pretty much standard on mountain bike wheels. This is to accommodate fatter tyres. That said, Fulcrum has gone as far as to test certain widths, claiming that 45mm tyres “perform very well”, so there is a range of 45mm tyres that have been validated by the brand.
While 47-50mm is said to be optimal for speed, Fulcrum’s spec sheets for both wheelsets state the rims can take up to 76mm tyres, if you want some serious cushioning.
Where the wheelset gets undoubtedly gravel (or even road) is that each wheelset benefits from a new 2-Wave Rim, featuring a mini-hook to keep wide tyres in place. But where these wheels get cool is in their profiles, as they use a waved profile that varies from 47mm to 52mm in depth. Fulcrum says that this “improves airflow management and reduces the yaw moment and frontal drag.”
Why two models?’ I hear you ask. Well, the Sharq GR utilises the full weight of Fulcrum’s engineering in pursuit of nothing but performance. It utilises FF100 carbon fibre, cup and cone bearing hubs, A3RO flat spokes and a 2:1 lacing pattern. The brand says that this set weighs 1,550g.
As for the Sonic GR, it’s less competition-focused, says Fulcrum. Instead, it uses FF80 carbon and sealed cartridge bearings with adjustable preload and round spokes. Apparently, this wheelset weighs 1,695g.
The benefits of wide rims and fat tyres… according to Fulcrum
Of course, Fulcrum has put in an awful lot of research into what wide rims and tyres bring to the table before concluding that they’re worth pursuing. First up, the brand reckons that it creates a better interface between the rim and tyre, with narrow rims resulting in the “lightbulb effect”, which is bad, says Fulcrum. The brand says that wide rims improve airflow and aerodynamics.
Fulcrum goes on to state that a wider internal width helps keep the tyre in a better shape under cornering loads by providing more support – any mountain bikers out there will know exactly what I mean.
Interestingly, the brand claims that wider rims reduce rolling resistance. Its research shows that narrow tyres can flatten more when weighted, which boosts deformation, worsening rolling resistance. However, a wider tyre doesn’t flatten as much, reducing rolling resistance, says Fulcrum.
Anyway, as for pricing, expect to spend £1,790 for a pair of mega-posh Sharq GRs, and £1,290 for some not quite as posh Soniq GRs.
2 thoughts on “Developed for modern gravel racing, Fulcrum’s Sharq GR and Sonic GR are optimised for 47-50mm tyres… and can fit up to 76mm”
“can fit up to 50mm tyres”
They can fit much wider tyres than that. Fulcrum’s marketing says they have been optimised for 47-50mm tyres (as becoming common for gravel racing), but the specs say they can be used with anything up to 76mm.
Soniq*
There will be a marketing guru crying that you missed the trendy q!