When it comes to gravel wheels, inner-wheel width is becoming a buzzword. Wider tires ideally require wider rims to support the sidewalls and keep the tires from rolling over during hard cornering. Shimano's latest GRX wheels, like many others, are wider than their predecessors.

The existing GRX wheels are an aluminum wheelset with a rim height of 22 mm and an internal width of 21.6 mm, available in 650b and 700c. These are not archaic numbers by any means, but by the standards of today's best gravel wheelsets, they are a bit outdated.

In contrast, Shimano has created a more modern rim profile with its all-new GRX wheels. According to Shimano, it can now accommodate tires from 32mm to 50mm. Perhaps even beyond 50mm would be possible, but the optimized sidewall support would likely be lost.

The depth of 30mm is an intermediate depth compared to competitors. Shimano states that this depth was chosen to improve performance in high winds. By not using a deep profile, the weight is also reduced to 1,461g (636g front, 822g rear).

Naturally, the rims are tubeless compatible, but it is unclear if the wheels will be set up tubeless at the time of sale or if it is up to the customer. There is also no mention of rim sizes; 700c is an obvious option, but the lack of mention of 650b suggests that Shimano sees the standard in this area as declining and not worth supporting.

The rims may have received a modern overhaul, but the hubs remain obsolete. The 24-spoke front and rear, center-locking discs, and through axles are all modern, but the cup-and-cone bearings deserve special mention.

Most high-end gravel wheelsets, especially carbon wheelsets, use sealed cartridge bearings. The GRX wheels use the same cup-and-cone system as the alloy wheels, which is obvious considering that Shimano's high-end Ultegra and Dura-Ace wheels still use loose ball bearings.

It will take some testing to see how well they hold up against the best gravel wheels on the market.

A complete set would require a budget of $1,399.99. Pricing in the UK has not yet been announced, but given that the price in the US is the same as the Ultegra road wheels, one would expect a comparable price in the UK, around £1,259.99.