Nextie Xiphias carbon rim
The Xiphias is the lightest fat-bike rim Nextie makes: a single-wall carbon rim in eight widths, from a 55mm 27.5+ crossover to a 120mm float rim, from 425 to 600 grams. On a fat bike, where the rim is the heaviest part of the wheel, that is where carbon saves the most.
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 Xiphias is for the fat bike that has to climb, and for riders who want one rim family to cover everything from plus tires to 6in snow tires. The 55mm takes 2.8 to 3.8in tires; the 80 and 85mm are the all-round 4 to 5in widths; the 95, 105 and 120mm are for 4.2in tires and up and deep snow. Every size is 32-hole and tubeless-ready.
Sizes, weights and prices
8 sizes, in 29in / 700c, 27.5in / 650b, 26in, 24in, drilled 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 |
|---|---|---|---|---|---|---|---|---|
| Xiphias 55 | 29in / 700c | 49mm | - | 607 | 425g | 2.8-3.8in | 32 | $365 |
| Xiphias 55 | 27.5in / 650b | 49mm | - | 430 | 425g | 2.8-3.8in | 32 | $365 |
| Xiphias 65 | 26in | 59mm | - | 425 | 425g | 3.2-4.5in | 32 | $385 |
| Xiphias 70 | 27.5in / 650b | 64mm | - | 510 | 510g | 3.2-4.6in | 32 | $395 |
| Xiphias 80 | 27.5in / 650b | 74mm | - | 569 | 580g | 3.5-4.8in | 32 | $415 |
| Xiphias 85 | 26in | 79mm | - | 530 | 530g | 3.8-5.0in | 32 | $425 |
| Xiphias 95 | 27.5in / 650b | 89mm | - | 568 | 600g | 4.2-5.5in | 32 | $445 |
| Xiphias 95 | 26in | 89mm | - | 544 | 600g | 4.2-5.5in | 32 | $445 |
| Xiphias 105 | 26in | 99mm | - | 544 | 585g | 4.6-6.0in | 32 | $465 |
| Xiphias 120 | 24in | 114mm | - | 490 | 600g | 5-6.5in | 32 | $525 |
How it compares
For more strength, the double-wall Black Eagle II 65, Wild Dragon and Drunken Rhinoceros add a second wall: heavier, stiffer, and rated for more system weight.
What the designations mean
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.
| Xiphias / Wild Dragon / Black Eagle / Drunken Rhinoceros | Nextie's fat-bike rims, named by model: Xiphias (single-wall, lightest) 55-120mm, Black Eagle 65mm, Wild Dragon 85-90mm and Drunken Rhinoceros 128mm (double-wall). |
|---|
Material and construction
The Nextie Xiphias is molded from carbon fiber in Nextie's Xiamen factory, in a UD (unidirectional) weave with a matte finish. The bed is tubeless-ready. Nextie rates these sizes for a maximum system weight of 134Kg; 140Kg; 146Kg; 157Kg; 177Kg; 185Kg; 200 Kg (rider plus bike and gear).
How Nextie tests the Xiphias
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.
Nextie's fat rims are tested for stiffness rather than hammer impact, since a 4in tire at 8psi is the impact protection. The single-wall Xiphias shares the molding and inspection process of Nextie's double-wall fat rims, and Nextie rates each width for its own maximum system weight, from 134kg on the 55mm to 200kg on the 120mm (see the table).
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.
There is no UCI approval for fat-bike wheels; the approvals below are Nextie's road and gravel certificates, from the same factory and test lab.
- 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 425g for the Xiphias 55 to 600g for the Xiphias 95. 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. Inner widths of 49, 59, 64, 74, 79, 89, 99 and 114mm decide the tire.
Value
Carbon fat rims from the big names cost more than many complete fat bikes. The Xiphias costs a fraction of that direct from Nextie's molds, and built here on a 150 or 197mm fat hub it makes a fat bike steer and accelerate more like a mountain bike.
How we build it
Choose the size, the wheel diameter and a drilling (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 Xiphias 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. If we lace this into a wheel for you, that wheel also carries ProWheelBuilder's own one-year warranty, which covers broken spokes regardless of cause and all wheel-related labor, including truing and rebuilding, for a year from purchase. Where a rim or hub is covered by its maker, we make the manufacturer's claim for you and coordinate it; where it is not, we offer an eligible replacement rim or hub at 25% off current retail. Shipping to and from us is the customer's. This cover does not extend to wheels built from components you supply yourself.
Full terms are on our Policies & Warranty page.
Nextie Xiphias questions
What does single-wall mean on a fat rim?
The Xiphias has one wall between the tire bed and the spoke bed instead of the two of a box-section rim. It saves a lot of weight on a rim this wide; the double-wall Black Eagle, Wild Dragon and Drunken Rhinoceros are stiffer and rated for more weight.
Which Xiphias width should I choose?
Match it to your tire. Nextie's tire ranges are in the table: roughly 55mm for 2.8 to 3.8in, 80 to 85mm for 3.5 to 5in, and 95mm and wider for 4.2in tires and up.
Is ProWheelBuilder the manufacturer of the Nextie Xiphias?
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 Xiphias 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.
