Nextie Premium RGX carbon rim
The RGX has the widest gravel bed Nextie makes: 38mm inside, for the biggest gravel and monster-cross tires. It comes in 45, 55 and 65mm depths from 440 grams, in the Premium edition with a three-year warranty.
Nextie designs and molds the rim; ProWheelBuilder is an independent wheel builder in Georgia, not the manufacturer. We build it into a complete wheel: pick the hub, spokes, nipples and lacing in the configurator and it ships laced, tensioned and trued.
Who it is for
The RGX is for bikepacking, rough gravel and monster-cross builds on tires of 50mm and up, and for riders who want a gravel wheel that will take a 2.2in mountain bike tire. The 38mm bed gives a big tire the widest footprint and the most support at very low pressure. Drilled 24, 28 or 32 holes, with the 32-hole build suited to loaded touring.
Sizes, weights and prices
3 sizes, in 29in / 700c, drilled 24h, 28h, 32h. Rim weights are Nextie's published figures; ERD is the effective rim diameter we cut spokes to, listed per wheel size.
| Size | Wheel | Inner width | Depth | ERD | Weight | Tire range | Drilling | Rim price |
|---|---|---|---|---|---|---|---|---|
| RGX 45 | 29in / 700c | 38.0mm | 45mm | - | 440g | 50-75mm | 24, 28, 32 | $315 |
| RGX 55 | 29in / 700c | 38.0mm | 55mm | - | 480g | 50-75mm | 24, 28, 32 | $335 |
| RGX 65 | 29in / 700c | 38.0mm | 65mm | - | 520g | 50-75mm | 24, 28, 32 | $355 |
How it compares
The Supreme SGV is lighter on a 32mm bed. The CGX is the 25mm road-gravel crossover. If your tires are 2.2in and up and the riding is singletrack, the mountain rims such as the VM are the better match.
What the designations mean
Standard, Premium and Supreme
Nextie builds every rim in one of three editions. The mold is the same; the carbon grade, the spoke-bed process, the tolerances and the warranty step up with each tier.
| Standard | Premium | Supreme | |
|---|---|---|---|
| Carbon fiber | Full Toray T700 | T700 with high-modulus T800 | T800 with ultra-light T1000 |
| Spoke bed | Standard layup | Independent mold for consistent spoke-hole thickness | Advanced Single-Point independent mold |
| Roundness / flatness | within 0.25mm | within 0.20mm | within 0.15mm |
| Factory warranty | 2 years | 3 years | 5 years |
| Built for | Reliable, cost-effective baseline | Balanced stiffness, deflection control and weight | Minimum weight with maximum impact resistance |
Tier specifications as published by Nextie.
Series codes
Every size in the list carries Nextie's own series code. Road and gravel codes are width classes, which set the tire size and the aero profile; MTB codes are duty cycles.
| Premium | Premium is Nextie's balanced edition: a T700 and high-modulus T800 carbon mix, an independent spoke-bed mold for consistent spoke-hole thickness, roundness and flatness within 0.20mm, and a 3-year factory warranty - stiffness, deflection control and weight in balance. |
|---|---|
| SGX / RGX | Wide and widest gravel: 32mm (SGX) and 38mm (RGX) beds for the biggest gravel tires, again impact resistance over aero. |
Material and construction
The Nextie Premium RGX is molded from carbon fiber in Nextie's Xiamen factory, in a UD (unidirectional) weave with a matte finish. Premium is Nextie's balanced edition: a T700 and high-modulus T800 carbon mix, an independent spoke-bed mold for consistent spoke-hole thickness, roundness and flatness within 0.20mm, and a 3-year factory warranty - stiffness, deflection control and weight in balance. The bed is tubeless-ready.
How Nextie tests the Premium RGX
Nextie publishes its own lab results rather than a marketing line. Rims are impact-tested on a drop hammer to the UCI wheel-approval protocol and beyond it (a weighted hammer dropped onto the built, tensioned wheel until the rim fails, the energy recorded in joules), checked for positive and lateral stiffness under load, pulled to destruction at the spoke hole, measured for runout and roundness as a built wheel, and heat-soaked at 80°C for four hours. Every edition also carries a roundness and flatness tolerance, an ASTM riding-condition rating, a maximum system weight and a factory warranty, listed below.
Premium gravel rims are molded from Toray T800 and T700 with rigidity and deflection controlled within 0.2mm, and rated ASTM condition 3 with a maximum system weight of 149kg on the NGX sizes; Nextie specifies 100 to 130kgf spoke tension and, on the hooked bed, 23 to 70psi for gravel tires. They share the factory's drop-hammer, stiffness and spoke-hole protocol with the Supreme gravel rims above, and carry a three-year warranty.
Certifications
The UCI's wheel approval procedure is the only independent certification that exists for bicycle rims: a wheel built on the rim is impact-tested and inspected under the UCI's protocol before it may be raced in UCI-sanctioned road, cyclocross and gravel events, and the certificate is published. Nextie has held UCI approval since September 2021 and adds models each year; it also states that its factory holds SGS test certification and industry production-system certifications, and it rates every rim to an ASTM riding-condition class.
No Premium gravel size carries its own UCI certificate yet; the approvals below are on Nextie's Supreme road and gravel rims, which go through the same factory protocol.
- NXT45RC Premium road rim — UCI wheel approval, September 2021 (certificate PDF)
- Alpha 50 Supreme road wheel — UCI wheel approval, 8 October 2025 (certificate PDF)
- Alpha 40 Supreme road rim — UCI wheel approval, 29 May 2026 (certificate PDF)
- Alpha 45G Supreme gravel rim — UCI wheel approval, 21 July 2026 (certificate PDF)
- Alpha 55G Supreme gravel rim — UCI wheel approval, 21 July 2026 (certificate PDF)
Source documents on nextie.com:
Figures, certificates and media are Nextie's own, published on nextie.com; ProWheelBuilder builds the rim into a wheel and does not run these tests.
Weight
Weights run from 440g for the RGX 45 to 520g for the RGX 65. Rim weight is rotating weight at the outside of the wheel, so a gram saved here is felt more than a gram saved on the frame. The 38mm inner width decides the tire.
Value
Wide carbon gravel rims are a small market, and the few big-brand options are priced accordingly. The RGX brings a 38mm carbon bed to the Premium edition, direct from Nextie with a three-year warranty; built here on the hub you choose, it costs about what wide alloy does elsewhere.
How we build it
Choose the size, the wheel diameter and a drilling (24h, 28h, 32h), and the configurator only offers hubs, spokes and lacing patterns that can actually be built with that combination. Start a build with the Nextie Premium RGX and the Custom Wheel Program opens with this rim already selected; from this page, the Build button carries the size, drilling and diameter you picked straight into the build. You can also send us a rim you already own with the supply-your-own option.
Spoke head is decided by the hub, not the rim: this rim builds equally well with J-bend or straight-pull spokes, and the configurator only offers the spokes that match the hub you pick.
Warranty
Manufacturer's warranty. Nextie warrants this product against defects in materials and workmanship. The duration, conditions and claim process are set by Nextie and can change without notice, so ask us and we will confirm the current terms before you buy.
ProWheelBuilder. Any wheel we build on this part carries ProWheelBuilder's one-year warranty in addition to the manufacturer's. Broken spokes are replaced for a year whatever the cause, and all wheel-side labor is included - truing, re-tensioning, rebuilding. Where the maker covers a failed rim or hub we handle that claim for you; where they decline, an eligible replacement comes at 25% off current retail. The customer covers shipping in both directions. Components supplied by the customer are not covered.
Full terms are on our Policies & Warranty page.
Nextie Premium RGX questions
Will an RGX take a mountain bike tire?
Nextie lists tires from 50 to 75mm, which covers big gravel tires and 2.0 to 2.25in mountain bike tires. Check your frame's tire clearance first.
Is the RGX tubeless-ready?
Yes. We tape it and fit a valve when you choose the tubeless option in the build.
Is ProWheelBuilder the manufacturer of the Nextie Premium RGX?
No. Nextie designs and manufactures the rim. ProWheelBuilder is an independent custom wheel builder in Georgia: we buy the rim from Nextie and build it into a finished wheel to your spec.
Can I buy the Nextie Premium RGX on its own?
No. We supply Nextie rims only as part of a wheel we build, so every rim is laced, tensioned and trued here before it ships.
How long will the wheel take?
Build time comes down to parts availability rather than bench time. The estimated ship date is shown in the configurator before you check out.
Not sure which size? Text or leave a voicemail on 470-253-0929 or email info@prowheelbuilder.com — you will be talking to the people who build the wheels.
