Gulo Composites GGX-SL Wheelset: At the Finish

Gulo equipped GT Grade Carbon Pro

Gulo Composites GGX-SL Wheelset: At the Finish – by MG

After six months of riding and yes, even a little bit of racing, it’s time to wrap up the long-term review of the GGX-SL wheelset from Gulo Composites. Do the innovative composite wheels from North Carolina deliver performance worthy of the lofty $2,625 asking price? We’ll give our final verdict here.

On the road again…
Star of the show: Gulo’s innovative braided composite spokes are half the weight of traditional steel spokes, yet offer greater resistance to impact-related damage.

In the last Checkpoint post of the review, I praised the GGX-SL wheels’ light weight, ride quality and overall feel. There really does seem to be something to Gulo Composites’ claims of a smoother riding wheel. Ridden back to back with other wheels, the improved ride quality is surprisingly apparent.

There’s also something special about the feel of ultralight wheels under acceleration and at 1,296 grams, the GGX-SL wheels don’t disappoint. Yet, despite the low weight, the wheels feel reassuringly stiff and strong when pushed hard through corners or rough terrain. That’s a tough balance to achieve, but Gulo Composites really nailed it when it comes to ride feel.

The braided composite spokes are very light too. On my digital scale, a Gulo spoke weighs 3g, while an equivalent DT 14/15g butted spoke weighs 6g. For the wheelset, that saves about 168 grams, which is pretty significant. A similar wheelset built from metal spokes would weigh about 1,460 grams, so the Gulo spokes definitely do make a difference on the scale.

Fortunately, I wasn’t able to directly test Gulo’s impact resistance claims for the composite spokes, but I’ve been given no reason to question them either.

Gulo GRX-SL rear hub
The Gulo ETI system rear hub spins smoothly on premium cartridge bearings. Shimano, SRAM and Campagnolo cassette bodies are available, but rotor mounting is Centerlock only.

With a 22mm internal width and traditional hook beads, the carbon fiber rims Gulo Composites uses on the GGX-SL wheelset are appropriate for gravel tires up to about 45c. In all honesty, I’d love it if the rims were a couple millimeters wider, but it’s not a deal breaker. That said, folks who prefer fatter (+50mm) tires might be better served by a bit wider rims.

Gulo’s ETI System hubs started out smooth and have broken in to be even smoother than when new. While they may not have the aftermarket name brand cachet of an I9 or King hub set, the Gulo hubs are strong performers nonetheless.

Bumps along the road

As mentioned in my Checkpoint post, the rear wheel did require a minor truing during testing. Gulo Composites has since changed the spoke prep compound they use when building the wheels, so this shouldn’t be an issue for anyone buying a set now. I didn’t have any follow-up issues after truing the rear wheel either, which is good.

Tubeless performance has been reliable overall, but it wasn’t without one hiccup. After about five months of use and several tire changes, I failed at installing a tire on the rear wheel. Nothing I tried would get it to bead up.

After speaking with the folks at Gulo Composites about my experience, they recommended I re-tape the wheel with new tubeless tape. Long story short, it worked and I installed the tire without further drama.

With a 22mm internal diameter and traditional hook beads, the GRX-SL rims work well with both tubed and tubeless tires up to about 45c wide.

What had happened? Apparently, over time the pneumatic pressure on the rim tape caused it to stretch and dip slightly into each of the rim’s spoke holes. It was just enough that the tire bead couldn’t achieve a sufficient seal to push the beads outward over the rim hooks, even using a compressor.

While it was a frustrating experience, the solution was easy. I should also mention that most wheel manufacturers recommend re-taping tubeless rims when tires are changed out. Had I followed that advice, I would have avoided the problem altogether.

Bottom line on the GGX-SL wheelset

Even with the minor issues encountered during the test period, I’m still impressed by the GGX-SL wheelset overall. Their positive impact on the ride quality and acceleration of our GT Grade Carbon test bike was easy to feel, particularly after riding other wheels on the bike.

The gravel wheelset market is ultra competitive right now, but the GGX-SL wheelset fits well into the premium high-end segment of the market. They aren’t inexpensive, but the performance the deliver on the road is compelling.

If you’re building your dream gravel bike, or are simply looking to spice up the performance of your current ride, Gulo’s GGX-SL wheelset is well worth a look.

Visit the Gulo Composites website to learn more about the GGX-SL wheelset.

NOTE- Gulo Composites sent over the GGX-SL wheels for test and review to Riding Gravel at no charge. We are not being paid nor bribed for this review and we will give our honest thoughts and opinions throughout.


Author: MG

Matt Gersib is the 2014 Gravel World Champion in the Fatbike category. He's also finished some of the most challenging gravel events in the country, including the Dirty Kanza XL, TransIowa and the Dirty Kanza 200, among others. In 2015, Gersib was an inaugural inductee into the DK200 "1,000 mile club" of five-time finishers. In addition to his gravel cycling, Gersib is an accomplished mountain bike racer, with numerous race wins and championships, including the 2012 Nebraska State Marathon MTB Championship.

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