Shimano GRX Carbon Wheels: Getting Rolling

Shimano GRX Carbon Wheels: Getting Rolling – by Guitar Ted

Shot of a pair of GRX Carbon wheels from Shimano with flowers and pepper plants
The new GRX Carbon wheels from Shimano

Last May we revealed the news here that Shimano was going to offer a GRX Carbon wheel in the Fall. Well, that time is nigh and we have a set of the GRX Carbon wheels in for review now. While the linked “Gravel Grinder News” post has a lot of the specifications in it, we will briefly cover those and then get to first impressions. A mid-term and final review will come in the following weeks and months.

Detail shot of the inner rim of a GRX Carbon wheel.
The new GRX Carbon wheels come pre-taped for tubeless and have a 25mm inner rim width.

What It Is: The GRX Carbon wheel set is aimed at the all-around rider who may be tackling races, but also for everyday adventures. Shimano claims that tires from 32mm to 52mm are the target size for the GRX wheels, so that covers a lot of ground and promises that the new wheels will be a versatile upgrade for most backroad/all-road type riding.

The rims are made from carbon fiber, of course, and have a 32mm depth, a 30mm width overall, and the inner rim width is 25mm. Shimano claims that the depth is good for less cross wind issues and will accelerate quickly as well as being better for climbing. The inner rim width is capable of giving the average gravel tire a better stance and volume for the rigors of gravel riding.

Hubs  image showing straight-pull spokes, 12mm through axles Center Lock brake rotor mount.
CenterLock brake rotor mounts, Hubs feature straight-pull spokes, 12mm through axles, and Shimano’s serviceable cup and cone bearings.

Other features include pre-installed rim tape and valves, so the GRX wheels are ready to go, as far as a tubeless set up, out of the box. The wheels come with an 11/12 speed Shimano free hub body (No alternatives offered) and are CenterLock rotor compatible. Of course, they are 12mm through axle standard 100mm/142mm OLD only. There is no 650B offering at this time.

Hubs feature Shimano’s cup and cone bearing system, 24 semi-bladed, straight pull, butted spokes, and external nipples. This should make replacing a spoke, if necessary, a little easier, albeit, straight pull spokes are not necessarily all that commonplace.

The claimed weight for the pair of GRX wheels is 1461 grams. The GRX wheels cost $1399.99 USD. Availability through local bike shops should be this Fall.

First Impressions: Out of the box I was impressed with what felt like a light wheel set. The stealthy black look of matte finished carbon with subtle graphics was nice. Personally, I don’t miss those “shouty” graphics wheels used to sport not all that long ago. I will only add that these subtle graphics don’t add any “parking lot appeal” though, if that is important to you. Me? I’m fine with this look.

That tape job! That has to be a machine-done process. It looks really well done. The valves have a nice plastic “foundation” which the Presta nut can lock down against, which is a nice touch. I noted that the valve base really sticks out a ways from the inner rim well. Better inflation/bead setting? Perhaps…

Okay, time for the moment of truth then with the digital scales. I found that the wheels weighed in at a respectable 1470 grams, so right in the ballpark for the claimed weight. Considering that valves and tape have added to this, the weight without those components likely would place these wheels right in at a hair over that 1400 gram line. this is an apples-to-apples guesstimate because I don’t have the exact bare weight and that is how other wheel companies weight their product. But suffice it to say that an “everyday” wheel set that weights under 1500 grams is pretty respectable.

 Detail showing the axle and wrench flats for the hub adjustment.
Detail showing the axle and wrench flats for the hub adjustment.

The hubs felt smooth and spun freely. You can see the wrench flats on the outer portion of the axle indicating that cup and cone arrangement Shimano is famous for. I was a bit surprised that the free hub was steel. Of course, no fancy ‘high-engagement’ ratchets or internals here. Just the tried and true pawl system Shimano doggedly sticks to for their hubs. This means that you don’t get that ‘high-engagement’ feel after a brief coast, but honestly, this is gravel riding, and do we really need that? Besides, high-engagement also generally means ‘high-drag’, so it is another example of compromises to an end.

Tubeless Set-up and Installation: I chose to use a set of Hutchinson Touareg tires we reviewed (here) and those were 45mm claimed width tires. They were easily mounted by hand with no tools and just a little ‘elbow grease’. I used WTB sealant to set the wheels up with and the tires pumped up and set up with my Topeak Joe Blow floor pump easily. (With valve cores in!) Pretty simple set up and it has proven to be rock solid so far. By the way, the 25mm inner rim width took the Touaregs from their previous 46mm width to just a hair under 47mm. So close that I’d call it 47 now, actually.

Shimano sent a set of new RT-MT800 rotors to mount on the new GRX wheels so those slipped on and were no issues to use on my Noble GX5 gravel bike which is already running GRX brake calipers. I then used my 11-40T XT cassette on the rear wheel and then all was mounted up with just a little tweaking to make everything work in harmony.

Guitar Ted's Noble Bikes GX5 set up with the GRX wheels.
All set and ready to ride!

So Far… Shimano releases a carbon wheel set with a modern, gravel friendly inner rim width of 25mm and at a reasonable price of 1400 bucks. The weight seems pretty good here with tubeless tape and valves already installed. I expect that the ease of set up will pair up with my expectations for easy use as well.

Carbon wheels are a boon to gravel riding since they cut down on the oscillations which can plague an aluminum wheel set in terms of high frequency vibrations. Handling should prove to be good, since carbon rims also tend to not deflect so easily which should result in a calmer ride on loose, crushed rock. I expect bearings to roll smoothly throughout the test and that the wheels will just not be an issue at any time in a negative way.

Will these new wheels from Shimano measure up? I like the inner rim width and the stance that this allows my Touaregs to have. The wheels look great, albeit maybe too generic! But the proof is in the riding, and that awaits me now out in the country. Stay tuned for a ride performance report coming in about a month or so.

For more on the Shimano GRX Carbon wheels see the webpage for them here;

Note: Shimano sent over the Carbon GRX wheels to Riding Gravel at no charge for test and review. We were not paid, nor bribed for this review and we always strive to give our honest thoughts and views throughout.


Author: Guitar Ted

Guitar Ted hails from Iowa. Home of over 70,000 miles of gravel and back roads. An inaugural member of the Gravel Cycling Hall of Fame and Co-creator of Trans Iowa in late 2004- Guitar Ted has been at the forefront of the growth of gravel events and riding since then. Creator of Gravel Grinder News in 2008, he produced the premier calendar of gravel and back road events. GT joined forces with Riding Gravel in late 2014.

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