Reinventing the wheel is literally what the cycling industry is all about. Every year hundreds of companies take their shot; so it’s rare when one unique design stands out, especially when that product is competitively priced.
I first rode Spinergy wheels with their unique flexible PBO spokes over a decade ago on 26-inch mountain hardtail. I remembered them as being light, fast and smooth riding, but really hadn’t seen the company’s name much till a few months ago. Spinergy had announced that their GXC gravel/cross wheels, with made-in-North America carbon rims, were receiving a significant price drop from $1,775 to $999 a pair. I immediately wanted to find out how this was possible—did they change something in the wheels or use cheaper labor or a new factory? More importantly, I wanted to see how these wheels would ride, adding carbon rims to the PBO spokes sounded like a great combination and something that other gravel and cyclocross riders might also be interested in.
Spinergy is located in Carlsbad, California and is where GXC carbon wheels go through 100% final quality control. The carbon rims aren’t manufactured there however, that is done at their factory south of the US border in Tijuana, Mexico. The old price point of $1,775 was a steep price to pay for any wheelset, although some notable brands like Enve frequently reach towards the $3,000/pair mark. Dropping the price to $999 makes Spinergy GXC wheels accessible to a much wider audience. Incredibly, according to Spinergy marketing guy Paul Cusick, the wheels have not changed at all, the company just decided to adjust their margin. Essentially, the wheels were not selling well at the $1,775 price, and many bike shops they talked to were confident the $999 price would move more product.
If you don’t know about PBO spokes, Spinergy has been producing wheels with PBO spokes for 20 years now. PBO, also known as Zylon, is short for polyphenylene bensobisoxazole, which are the type of fiber that the spokes are made from (over 30,000 strands in each). A quick Google search will tell you that PBO is a high-performance fiber with very high tensile strength, a high Young’s modulus, and excellent thermal stability. A high Young’s Modulus means PBO is resistant to stretching—perfect for an application under tension—like a bicycle spoke. Spinergy seems to have a lock on using PBO in the bike industry, but other applications include space hardware, body armor, sports racquets, snowboards, and the medical world.
The PBO fibers are sealed in a sheath to protect them from UV light and the environment—conveniently this also allows the spokes to come in ten different colors. The final PBO spoke, sheath and all, is said to be three-times the strength of stainless steel at half the weight. Finally, each GXC wheel receives 24 of these in a combination radial and two-cross pattern.
The GXC’s carbon rims are tubeless-compatible carbon fiber clincher rims with a 32mm depth and 18mm internal / 24mm external width. The carbon rim is constructed with a foam core inside of it that does a couple things. First, during construction the foam aids in carbon compaction, thus reducing any voids. Secondly, the foam is another level of vibration reduction similar to what Spank Industries has promoted with their Vibrocore bars and wheels for MTB and gravel applications.
The thing that truly sets gravel bikes apart from their road brethren are those big tires. Fat tires on a gravel bike make everything more fun and capable than just taking your road bike off-piste. So you may have already noticed that an 18mm internal rim width will max out with a 40mm tire width (Spinergy’s recommended maximum). While 40mm is plenty wide for many gravel escapades, if you are of the “more is better” school of thought then you’ll be happy to know that right at the end of my evaluation period Spinergy announced their new GXX wheels with a 24mm internal width for 40mm and wider tires—everything on the GXX wheels is the same as the GXC—even the $999 price. GXX wheels will also be available in a limited edition with ceramic bearings and a double padded wheel bag for $1199. Spinergy doesn’t currently have a 650b carbon rim option if you like rolling low, but they do have an alloy wheelset with 650b rims and PBO spokes available for $599.
Spinergy uses proprietary, CNC-machined hubs designed with straight-pull spoke flanges and aerospace-grade aluminum axles, rolling on Enduro sealed bearings with an aluminum freehub body made by Hadley. You can request either SRAM X-D driver body or Shimano 11-speed freehub body options with the wheels while micro spline Shimano 12-speed is coming. The rear hub comes with a 12 x 142mm thru or a QR axle. The front with QR and 12mm or 15mm thru-axle options.
I paired my wheels with WTB’s new and aggressive 40mm Raddler gumwall to check out the knobbier end of the gravel tire spectrum. I ran the tires tubeless with Stans fluid and they mounted up easily with just a floor pump. Although the tires are a little on the heavy side at 490 grams each I still lost about 85 grams per wheel when I swapped out my old Giant CXR-1 alloy hoops with Goodyear Connector 40mm tires to the GXC/Raddler combo. The GXC wheels by themselves weigh 1,495 grams a pair, and it’s important to note more of the weight is concentrated at the hub area than would be on a stainless spoke wheelset so these have less rotating mass, which typically equates to good acceleration and climbing.
Spinergy GXC wheels look cool and hi-tech with great potential for color coordination if that’s your thing, but more importantly, their design has real substance as it improves your ride quality. PBO spokes transmit vibrations at a lower frequency than stainless steel spokes so even though they are stronger, the ride is not as harsh. When you add the foam core carbon rims to the equation, then the GXC models really takes things up a notch. The ride is kind of like the difference between an all-alloy frame bike and a well-built carbon frame—it’s smoother, more controllable, and more comfortable, especially when the miles add up.
I rode the GXC wheels for several months on a number of shorter dirt, gravel, pavement and mixed routes during the Southern California quarantine shut down. The wheels felt light and snappy with fast acceleration and never flinched riding through rocky sections or bouncing over rough curbs and pavement. All in all, I had no complaints and piled on a list of new PRs with this wheel and tire combo. The tires are a bit loud on pavement and if my goal had simply been Strava PRs I’m sure there are faster tire options, especially on pavement—the Raddlers are super fun and capable off-road though.
I didn’t experience any issues with my GXCs. They stayed straight and true and the carbon rims never flinched despite repeated flogging in the rocks. If something does go wrong with them however Spinergy offers a 2-year warranty and then a lifetime crash replacement/trade-in program so you would get a discount on the replacement should that be necessary.
Less rotating mass and a smooth ride make the Spinergy GXC a joy to pedal on shorter rides, but the benefits really add up the farther you travel. They aren’t alloy-rim cheap, but the fact that you don’t have to spend as much for the wheels as you did on your carbon frameset makes the price of admission much easier to swallow. If you want to run 40mm or wider tires, Spinergy just announced their GXX model wheels with nearly identical specs except for having wider rims.
Color: Black, Blue, Red, Yellow, White, Orange, Green, Pink, Purple, Grey
Weight: 1,495 grams / pair
Hub: Spinergy Proprietary with Hadley Freehub body
Wheel Type: Road/All-Road/Many Road/No Road/Gravel/Dirt
Internal Width: 18mm
Spoke Count: 24
Recommended Tire Width: 32mm – 40mm
Driver Options: XDr or HG-EV, micro spline to come
Brake Options: 6-bolt
Hub Spacing: 100/142/420
Looks: Hi-Tech NASA Gravel