Roval C38 Carbon Wheelset — Is It Worth the Upgrade?

The Roval C38 review I wish I’d found before spending three weeks down a research rabbit hole would have saved me a lot of time. I bought these wheels after my third season on aluminum hoops, convinced I needed to stop leaving speed on the table. What I didn’t expect was how much the C38s would change the texture of long rides — not just the numbers. I’ve now put roughly 4,000 kilometers on this wheelset across flat centuries, punchy gravel-adjacent roads in Northern California, and a few genuinely miserable wet rides. Here’s what I actually think.

Roval C38 Specs and What You Get

Let me lay out the numbers first, because the spec sheet tells part of the story.

• Rim depth: 38mm
• Rim width (external): 28mm
• Rim width (internal): 21mm
• Weight (wheelset): 1,490g for the disc brake version — front 640g, rear 850g
• Hub: DT Swiss 350-based with Roval’s Spoke Torque Control system
• Spoke count: 21 front, 24 rear
• Recommended tire width: 25–32mm
• Retail price: $1,600 USD for the disc version

That 21mm internal width is the detail that jumped out at me when I first pulled them out of the box. My previous wheels ran a 17mm internal, and the difference in how a 28mm tire seats and rolls is not subtle. The wide channel lets the tire take a more rounded profile, which translates directly to compliance and cornering stability — more on that in the next section.

At $1,600, you’re competing with the Zipp 303 Firecrest (around $1,900 for disc), the Hunt 4454 Aero Disc ($1,200), and the Bontrager Aeolus Pro 37 ($1,450). The Roval sits in the middle of that pack on price, but the DT Swiss 350 hub internals give it a durability argument that the house-brand hubs on some competitors can’t match. I’ve had to replace a freehub body on a cheaper wheelset after 2,500km. Replacing the DT 350 internals is a $30 fix you can do on your kitchen counter.

Probably should have opened with this section, honestly — the hub choice alone makes a compelling case for the C38 at this price point, and most reviews gloss over it.

Ride Quality — How They Feel on the Road

Slapped onto my Specialized Tarmac SL7 with 28mm Pirelli P Zero Race tires at 72 psi, the first thing I noticed was how the front wheel tracked in a slight crosswind on the first open stretch of my regular Tuesday ride. The 38mm depth sits in a sweet spot — you feel the wind. It’s not threatening, just present. Compared to the 50mm hoops I borrowed from a friend for a week, the C38s felt planted and predictable. I didn’t have to fight the front end on an exposed ridge road that usually punishes anything over 40mm.

Acceleration is where carbon clinchers earn their reputation. Hard. The C38s spin up noticeably faster than my old Mavic Aksium Race wheels, which weighed in at 1,870g as a set. That 380g reduction matters most in the first few pedal strokes out of a corner or off a stoplight. Sprint efforts felt snappier — not dramatically so, but consistently enough that I stopped attributing it to good legs after the fifth or sixth ride.

Rough Road Behavior

The stretch of frontage road I use for intervals is chipseal-heavy — the kind of surface that has eaten through bar tape and rattled bottles loose. Running a 28mm tire at lower pressure than I’d ever trust on a narrow rim (65 psi instead of my old 80 psi), the C38s absorbed the buzz in a way that let me hold aero position longer without my hands going numb. This isn’t marketing language about “compliance.” It’s the mechanical reality of a wider rim profile paired with a correctly inflated tire.

That said, I did hit a sharp square-edge pothole at about 35 kph on a descent during my second month with these wheels. My heart rate spiked. The rim survived without a mark, and the tire didn’t burp air, but I learned to stop assuming carbon automatically means fragile — and also to stop taking descents I don’t know well at full commitment speed.

Crosswind Handling

The 38mm depth makes the C38 genuinely manageable in crosswinds up to about 25 kph. Above that, you’re making corrections. Nothing sketchy, but you feel it. Riders who regularly battle exposed coastal roads or high-desert conditions should know that 38mm is not a magic number that eliminates all aerodynamic influence. It just keeps things predictable.

Braking Performance

I’m reviewing the disc brake version exclusively — I haven’t ridden the rim brake C38, and I’m not going to speculate about it.

The disc version uses a standard 6-bolt rotor interface, 160mm front and rear by default. Pad compatibility is broad. I’ve used Shimano L04C metal pads and SwissStop Disc 29 organic pads with equal success. No glazing, no squeal after bedding in over about 40km of light use. Wet braking is where disc really shines on a carbon rim, and the C38 benefits from that entirely — there’s no carbon braking surface to worry about, no fade in long descents, no heating issues.

Wet Condition Performance

Caught by an unexpected late-October rainstorm on a 90km route with no good shelter options, I rode the last 25km in steady rain on unfamiliar descents using the C38s with rotors I hadn’t recently serviced. Braking feel was progressive and consistent the entire time. No drama. The only variable I’d flag is rotor contamination if you’re using a bike stand near chain lube spray — keep the rotors clean and the performance follows.

One honest note: I initially mounted 160mm rotors front and rear and found the rear felt slightly grabby in technical situations. Switching to a 140mm rear rotor (a common setup on endurance bikes) balanced the feel considerably. That’s not a C38 issue, but if you’re setting up a new disc wheelset for the first time, it’s worth knowing.

Who Should Buy the Roval C38

Here’s the clear answer after four thousand kilometers of actual riding.

Buy the C38 If You Are

• An endurance rider who wants aerodynamic benefit without the handling anxiety of deep-section wheels
• Someone who rides mixed surfaces and needs a rim wide enough to support 28–32mm tires properly
• A rider who values long-term hub serviceability over chasing the lowest possible weight number
• Upgrading from aluminum and want a single wheelset that works across most conditions

Skip the C38 If You Are

• A dedicated climber — at 1,490g, wheels like the Roval Alpinist CLX (1,175g) or Hunt 3450 Gravel Carbon (1,340g) make more sense where vertical meters are the priority
• Budget-constrained — $1,600 is real money, and the Hunt 4454 Aero at $1,200 closes a lot of the performance gap for less
• Expecting wind-tunnel gains to show up in every ride — on rolling terrain with variable pacing, aero wheels return less than steady-state testing suggests

The Roval C38 is a wheelset built for people who ride a lot of different roads and want one answer that’s rarely wrong. It doesn’t lead any single category — it’s not the lightest, not the deepest, not the cheapest. What it is, is consistently good. The DT Swiss 350 hub, the wide 21mm internal channel, the manageable 38mm depth in crosswinds — those are deliberate, mature engineering decisions that show up every single ride. For most road cyclists who clock 5,000 to 10,000km a year on mixed terrain, that’s exactly the wheelset you need.