Forty-five minutes into a fast gravel race, the group is strung out over hardpack and dry gravel roads. Everyone is riding a 40 to 45mm tire, and the bikes are set up for speed. Every wheel review you read says the same thing: go wider. For most gravel riders that is right, and it is why we build our gravel rims as wide as we do. But rim width is a match between rim, tire, riding style and terrain, and for one specific rider a slightly narrower rim is the better choice.
Why wide is better for most gravel riders
A wider internal width supports the tire sidewall along its full height and gives the tire a rounder profile. That lets you run a lower pressure for grip and comfort without the tire folding in a corner, and it opens up bigger tires: the Anath 423 SL has a 33mm internal width for tires from 40mm up to 62mm, and the SandStone SL has 37mm internal for tires up to 66mm. If you ride rough terrain, load your bike for bikepacking, or like the volume of a big tire, a wide rim is the right tool, and that is where our wide rims come in.
The rider for whom a narrower rim is better
Some riders sit in a different corner of the gravel market. They race or ride hard, they prefer tires around 45mm, and they ride mostly on smooth gravel: hardpack, fast gravel roads, well-kept tracks. When all three describe you, the extra width of a wide rim gives you less, because your tire, your speed and your terrain do not ask for it. What you want then is a rim that is matched to a 40 to 45mm tire, light, and aerodynamic. That rider is who we made the Anath 456 SL for.
What a 26.5mm gravel rim width does for a 40 to 45mm tire
A widely used guideline based on ETRTO ranges puts tire width at between 1.45 and 2 times the internal rim width, as this rim width calculator explains. For a 26.5mm rim, that works out at roughly 38 to 53mm. We rate the Anath 456 SL for 38 to 50mm, and we designed the width around the middle of that range: 40 to 45mm tires.
In that range, the rim supports the sidewall and the tire keeps a round profile, so you can still lower the pressure for grip and comfort. The hookless rim also makes tubeless setup easy. Hookless rims do come with their own tire compatibility and pressure limits, so check our Size & Pressure Chart for the pressure to start from. The rim itself weighs 420g.
Why 45mm deep
The 45mm depth is what we consider the ideal height for this kind of riding. It is deep enough to give an aerodynamic advantage at race speed, and deep enough to make the rim stiff, which you notice when you sprint out of a corner or push a big gear on a rolling course.
Speed is what makes aerodynamics worth it on gravel, and gravel keeps getting faster. Cameron Jones won the 2025 Unbound Gravel 200 in 8 hours 37 minutes, an average close to 38 km/h over the roughly 325 km course, and Escape Collective’s analysis notes that winning times have dropped by around 13% over the past few editions. Even over the 565 km of the Unbound XL, the winner averaged 32.4 km/h. At those speeds the shape of the wheel starts to matter on gravel as it does on the road.
The rest of the build
Under the carbon, the ART asymmetric rim design moves the spoke bed so the spoke tension on both sides of the rear wheel comes closer together. A more even tension keeps the wheel stiff and stable, and it lowers the chance of a spoke going slack under load. DT Swiss 240 EXP Straight Pull hubs, whose ratchet system engages the moment you accelerate, and 24 Alpina Ultralite aero spokes front and rear complete a wheelset that weighs 1358g.
Is it the right wheel for you?
Choose the rim for the tire, the style and the terrain you actually ride. If that is a tire around 45mm (up to 50mm at the most), a fast style and smooth gravel, the Anath 456 SL is built for you. If you ride bigger tires, rougher terrain or loaded bikes, look at the wider Anath 423 SL or SandStone SL instead.
View the Anath 456 SL in our webshop.
