Nextie Supreme SGV carbon rim
The SGV is the Supreme gravel rim for big tires: a 32mm inner width in the T800 and T1000 Supreme layup, from 340 grams in the 39mm depth. It is the lightest way to run a 45 to 50mm gravel tire, with a five-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 SGV is for gravel racers and long-distance riders on wide tires. The 32mm bed lets a 45mm-plus tire sit square at low pressure, which is where grip and comfort come from on rough gravel. The 39mm is the light, nimble choice; the 49mm is the race depth; the 64mm is for fast, open courses. Drilled 24, 28 or 32 holes.
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 |
|---|---|---|---|---|---|---|---|---|
| SGV 39 | 29in / 700c | 32mm | 39mm | 562 | 340g | 51-75mm | 24, 28, 32 | $345 |
| SGV 49 | 29in / 700c | 32mm | 49mm | 542 | 380g | 51-75mm | 24, 28, 32 | $365 |
| SGV 64 | 29in / 700c | 32mm | 64mm | 512 | 440g | 51-75mm | 24, 28, 32 | $395 |
How it compares
The Premium RGX goes wider still, to a 38mm bed, at more weight. The CGX is the narrower 25mm crossover. On the Supreme side, the Ocean 45G and the Alpha 45G and 55G are 25mm-bed rims for faster, narrower gravel.
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.
| Supreme | Supreme is Nextie's top edition: a T800 and ultra-light T1000 carbon blend, the Advanced Single-Point independent spoke-bed mold, roundness and flatness held within 0.15mm, and a 5-year factory warranty - the lowest weight Nextie can reach with the highest impact resistance. |
|---|---|
| SGV / NGV | The Supreme-edition gravel beds: SGV (32mm) and NGV (27.5mm) in the T800 / T1000 layup - the lightest way to run a wide gravel tire. |
Material and construction
The Nextie Supreme SGV is molded from carbon fiber in Nextie's Xiamen factory, in a UD (unidirectional) weave with a matte finish. Supreme is Nextie's top edition: a T800 and ultra-light T1000 carbon blend, the Advanced Single-Point independent spoke-bed mold, roundness and flatness held within 0.15mm, and a 5-year factory warranty - the lowest weight Nextie can reach with the highest impact resistance. The bed is tubeless-ready. Nextie rates these sizes for a maximum system weight of 149Kg; 159Kg; 174Kg (rider plus bike and gear).
How Nextie tests the Supreme SGV
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.
The Alpha 45G is Nextie's lab benchmark for the Supreme gravel rims: a 24.5kg drop hammer from 499mm gives 120J, above the UCI standard, with one sample surviving to 130J; positive stiffness of 265 to 267 N/mm against a 100 N/mm reference, lateral stiffness of 42 N/mm against a 6 N/mm reference, and five spoke-hole pull tests from 423 to 543kgf with no cracks. The layup is Toray T1100 with M46J high-modulus fiber, the built wheel is heat-soaked at 80°C for four hours, the Alpha 45G and 55G were UCI-approved on 21 July 2026, the maximum system weight is 166kg and the warranty is five years.
Nextie's test videos
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.
The SGV sizes do not carry their own UCI certificate; in the same Supreme gravel edition, the Alpha 45G and Alpha 55G are UCI-approved.
- 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:
- UCI approval certificate, Alpha 45G (PDF)
- UCI approval certificate, Alpha 55G (PDF)
- Nextie: Alpha 45G lab results
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 340g for the SGV 39 to 440g for the SGV 64. 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 32mm inner width decides the tire.
Value
The SGV sits at about half the price of the boutique carbon gravel rims it is measured against, with Supreme fiber and a five-year warranty direct from Nextie's molds. Built here on the hub you choose, it makes a top-tier gravel wheel set at a mid-range price.
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 Supreme SGV 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 Supreme SGV questions
What tire width suits the SGV?
Nextie lists 51 to 75mm for the 32mm bed. In practice it is happiest from about 45mm up, where the wide bed keeps the tire's sidewalls upright at low pressure.
What is the difference between the SGV and the SGX?
Both are 32mm gravel beds. The SGV is the Supreme-edition version in the lighter T800 and T1000 layup with a five-year warranty; the SGX is the Premium version. We offer the SGV.
Is ProWheelBuilder the manufacturer of the Nextie Supreme SGV?
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 Supreme SGV 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.
