Having wowed us last month with the extraordinary road-focussed MCC DX, French manufacturer Corima has launched another wheelset, this time for gravel.
The new G30.5 is a premium 30.5mm-deep 700c carbon-rimmed wheelset designed for the chunky tyres favoured by gravel and adventure riders.
Hookless rims and new DT Swiss hubs
While the MCC DX features a unique full-carbon construction, the new G30.5 is much more conventional, with carbon rims laced to standard hubs using ever-popular stainless steel Sapim CX-Ray spokes, laced 24 front and rear.
The hubs in question are the recently announced updated version of the benchmark DT Swiss 240, and Corima has opted for the standard J-bend flange option, which should make sourcing spares straightforward.
The G30.5s rims are hookless (Corima calls them TSS or Tubeless Straight Side) with an internal width of 22mm, which is very wide compared to conventional road rims but pretty middle-of the road compared to the latest gravel-specific wheels.
The new Zipp 303 S, for instance, has an internal width of 23mm, while the Enve SES 3.4 AR Disc is a chunky 25mm.
Externally, the G30.5s measure 28mm wide and Corima has designed them to work with tyres from 28 to 60mm wide, with a maximum allowed pressure of 5 bar (72.5psi), coincidentally the exact same figure quoted for those Zipps.
Incidentally, the G30.5 is described as “tubeless-ready”, and we're awaiting confirmation of whether this actually means tubeless-only, as hookless rims are typically not suitable for standard road or gravel clinchers.
Update 18 May 2020: According to Corima's UK representative, any gravel tyre can be used including standard clinchers with tubes, which is surprising given the hookless rim design. There is currently a list of six approved tubeless tyres on the Corima website (note that at the time of writing, some of the rest of the spec info is clearly wrong, this is apparently due to be corrected). Given the general uncertainty over tubeless tyre compatibility, we would always recommend checking and double checking with the wheel maker if you're unsure about a particularly rim-tyre combination. Getting this wrong is potentially very dangerous.
In any case, Corima notes that the G30.5's rims "have been designed to strictly adhere to the ETRTO standards", with easy tyre seating but no danger of them coming off.
Like the MCC DX and indeed all of Corimas carbon wheels, the new G30.5 uses a ‘torsion box’ rim design with a horizontal internal reinforcing member and a ‘structural foam’, which claim to add stiffness and absorb road vibrations.
Claimed weight for the G30.5s is 725g for the front and 825g for the rear, for a claimed total of 1,550g. This figure includes tubeless tape and valves.
As you’d expect for a brand new gravel wheelset, these are disc-only, and the hubs accept centerlock rotors.
The G30.5 is available to buy now, retailing at £2,010. Pricing in other territories is to be confirmed.
