The first commercially available pre-built wheelset was the Mavic Cosmic released in 1994. Prior to that wheels were custom-built from their individual components.
Nowadays, pre-built wheelsets options abound. With the majority of carbon wheel production coming out of Asia, companies can source wheels from a catalog of manufacturers and brand them their own.
Irwin Wheels is one of the relatively new wheel companies here in the U.S. scene. Earlier this year, we reviewed the company’s Kova XC 29er carbon tubeless clinchers.
Irwin Cycling started as an OEM partner, producing wheels for many well known brands. According to the company, Irwin does its own design and has its own facility for testing products. During the development of its new AON line of wheelsets, Irwin Cycling spent time in a low-speed wind tunnel in San Diego to improve the aerodynamics of its products.
The Irwin AON GX 35 carbon tubeless clincher wheelset is built specifically for the gravel and adventure set.
We have put some good gravel and high-volume cyclocross miles into our set of AON GX35 wheelset. Read on to find out if its read to go from the wind tunnel to your next two-wheel adventure.
Irwin AOX GX 35 Carbon Tubeless Clinchers
The AON GX 35 wheelset comes in both 700c and 650b models. We reviewed the 700c version.
The AON GX 35 has a 35mm deep carbon rim that is 30mm wide with a 24mm internal width and a hookless wall. The wide rim is asymmetrical with offset spoke holes.
The rims come pre-taped. The center channel of the rim is wide and shallow, bead shelf is has a slight lip, but it’s not prominent under the tape, but palpable.
Irwin does not recommend a tire narrower than 35mm and with a 24mm internal width on a hookless design, we did not feel a tire narrower tire would be appropriate.
Irwin Cycling laces the asymmetric AON GX 35 rims to large flange hubs, thoughtfully designed in-house. The flange spacing is 55.6mm for the rear, wider than many other 11-speed hubs in the industry, which hover in the lower 50mm range. That gives a wider bracing angle.
The wheels feature a range of compatibility with end caps for quick release, 12mm and 15mm thru-axle front and quick release and 12xx142mm rear.
Combined with asymmetric rim drilling that evens the left and right side spoke tension, the AON GX 35 design looks durable.
The freewheel design has 6 pawls, 3 engaged at any time with 3 teeth each. The remaining 3 pawls are in position to offer fast 3.75-degree engagement. The pawls use leaf springs and the 48-tooth ratchet runs quite silent.
Twenty-four Sapim D-Light double butted j-bend spokes (2.0/1.6/2.0) join the hubs to the asymmetrically drilled rims with a 2x pattern using external nipples. Irwin Cycling says the rims have reinforcement only at each spoke hole, not along the entire rim to minimize rotating weight. The high wide flanges with the asymmetric rim drilling yield a wide bracing angle with reasonable symmetry. The wheels are handbuilt to precision with stress relieving of the spokes.
Our scale tipped at 730 grams for the front wheel and 827 grams for the rear with a Shimano compatible cassette body (1,557g total). A sub-1600 gram weight is on the light side of average for this category. It is not as light as the Stan’s Grail CB7 but lighter than the similar Bontrager Aeolus 3.
Well-designed with construction to high standards, the Irwin Cycling AON GX 35 wheelset arrived ready to ride.
I used a Bontrager CX0 38mm TLR and the WTB 42mm Resolute with the AON GX 35 wheels. For 38mm and larger tires, I prefer a compressor to rigorous pumping. With that, I easily mounted the tires on the pre-taped rims.
When deflated, the tires stay on the bead shelf, which is indicative of a good match. It is actually a bit of a bear to wrestle off the deflated tire WTB tire.
I have come to like wider tires for all my mixed terrain riding since big tubeless tires have become a bit lighter. If I mounted twin Maxxis Rambler 700c x 40mm tires, I’d have a reasonably light, wide racing setup.
Even with the WTB Resolute 700c x 42mm tires, it’s within a 100 grams of the Bontrager Aeolus 3 setup with Ritchey Shield 700c x 35mm tires for non-UCI local cyclocross racing. Put the Shields on the Irwin AON GX 35 and I’m 50 grams ahead. All said that gram counting is fun, but performance is what ultimately matters.
The Irwin AON GX 35 wheels have been a very reliable setup with tubeless tires The tires fit snugly, have not burped and stay on the rim when deflated. The Bontrager CX0 38mm fits more loosely than the WTB Resolute, but we never had a problem, and it was easier to remove.
The AON GX 35 wheels add a nice width to the tires and although barely noticeable, the wide rims allowed a bit more tread to hit the ground than a 21mm internal width rim would.
The Irwin AON GX35 wheels mounted with wide tubeless tires provided an enjoyable ride. They’re stiff enough in corners to not rub and have held up the bottoming out of really low pressure tires.
On one bumpy, rocky downhill stretch, with a rear tire puncture, the rim bounced along with only the flat tire as cushion. No problem. No crack or delamination, and the tire did not unseat. The wheel stayed round and true. I plugged the tire, added extra sealant and went on my way.
The AON GX 35 wheelset has endured long mixed-terrain rides with mountain bike singletrack that is the realm of cross-country mountain bikes. I rode them in cyclocross practices and participated in local cyclocross races with fat tires aboard.
In the latter cases, I’ve enjoyed the lines I can take with 42mm tires and the bump smoothing quality. The demerit is accelerating the extra quarter to half a pound compared to narrower and lighter tires or a pound-plus compared to racing tubulars.
There’s a lot of good wheelsets out there. It’s hard to know what the story is for each company or what actual design elements went into the wheels.
A company like Irwin Cycling, trusted by OEM for wheel design and construction might get our trust too. The AON GX 35 we rode is a proven set for the mixed-terrain rides we’ve taken them on. The wide rim profile provides room for high-volume gravel tires and the rims stayed true, even when bottoming out on a flat tire.
With a 35mm minimum tire width, the AON GX 35 wheelset is ideal for gravel riding—but will leave you spaced out of UCI cyclocross racing. That said, if high-volume ’cross is your thing, the wheels can certainly serve double duty.
Irwin AON GX 35 Specifications
Weight: Front: 730g (actual), Rear: 827g (actual), Total: 1,557g (actual)
Rim: Carbon, 700c, tubeless-ready, hookless design
Width: 24mm internal, 30mm external
Hubs: Centerlock, 6-pawl, 3-tooth, 3.75-degree engagement
Axles: End caps for quick release, 12mm, 15mm thru-axle front; quick release, 12x142mm thru-axle rear
More Info: irwincycling.com