The all-new carbon GRX wheelset drops ~350g off the alloy set’s claimed weight, shedding all of that weight from the swap to carbon rims.
The new option provides a drastic reduction in rotational mass, so it should provide a huge improvement in acceleration. And, they do that while getting both wider and deeper!
The new WH-RX870-TL GRX Carbon wheels will only come in 700c versions, whereas the original alloy models launched with 700c and 650B sizes. All are tubeless ready.
The new carbon rim is 25mm wide internally and 32mm deep, compared to 21.6mm internal and 22mm deep for the alloy rims. So, presumably, a bit better aerodynamics, yet tough enough for (in their words) serpentine singletrack or bushwhacking along old goat paths.
While some of their sponsored riders have opted for Dura-Ace wheels in the past, these shallower GRX Carbon wheels provide the stiffness and lighter weight, but in a shallower depth that should be better for the crosswinds at courses like Unbound. And probably a bit more compliant.
Shimano GRX Carbon wheelset pricing & specs
External width is 30mm, and they’re compatible with 32mm to 50mm tires. Here’s the full spec list:
- Designed for 32-50mm tire widths
- 25mm internal and 30mm external rim widths
- Rim Height: 32mm
- Cup-and-cone ball bearing hubs
- 24 spoke count
- Weight: front wheel 639g, rear wheel 822g, total weight of 1,461 grams
MSRP for the wheels is $1,399, almost a thousand dollars more than the alloy version, but still a bit of a bargain for a wide, light carbon wheelset…and especially one from Shimano.