Astral Serpentine X Carbon Rim
The Astral Serpentine X is the wider version of Astral's carbon all-road rim: the same moderate depth and Tubeless Easy bead as the Serpentine with a wider inner bed that gives a 38 to 45mm gravel tire a square, stable shape at low pressure. It is the Astral carbon rim for gravel-first drop-bar bikes that still see fast road miles.
This page covers the Astral Serpentine X Carbon Rim in 29in. The Serpentine X is sold here only inside a wheel we build: choose the hub, spokes and nipples in the configurator and the finished wheel ships from Georgia, laced, tensioned and trued by hand.
Design and construction
The Serpentine is a carbon disc rim with a wide inner bed that gives a 30 to 35mm tire a round, fast profile, a section deep enough for a real aero benefit on the road and shallow enough to stay comfortable on dirt, and Astral's Tubeless Easy bead shelf that seats a tire with a floor pump. The spoke holes are angled toward the hub flanges so the nipples sit straight, and the layup adds material at the bead and spoke bed. External nipples, standard J-bend spokes, disc only. The Serpentine X is the wider version for bigger tires.
How it rides
A Serpentine X wheelset is fast and stable on gravel and quick enough on the road that you do not miss a narrower wheel. The wide bed lets you run a 40mm tire soft for grip and comfort, the carbon rim takes the sting out of washboard, and the depth helps on the fast flat stretches between the dirt. For road-first riding the Serpentine is the better bed.
Specifications
| Wheel size | 29in |
|---|---|
| ERD | 594 (29in) |
| Inner width | 30 mm |
| Depth | 25 mm |
| Drillings | 28h, 32h |
| Weight | 500g (700c/29in) |
| Material | Carbon Fiber |
| Tire type | Clincher Tubeless Compatible |
| Brake | Disc |
| Nipples | External |
| Finishes | black |
This version
This version is the Serpentine X in 29in, drilled 28h, 32h, about 500g, 30mm inside, 25mm deep, disc. Where the same rim is sold in another size or brake type, that is a separate listing with its own page.
The disc version of the Serpentine X has no brake track, so the sidewall is a plain extrusion that saves a little weight and never wears; it is the one to choose for any disc-brake frame. The rim-brake version, listed separately, has a machined sidewall.
Sizes, fit and compatibility
The Astral Serpentine X Carbon Rim comes in 29in and 28h, 32h drilling. It is a disc-brake rim. We build the Serpentine X on DT Swiss 350, 240 and 180, White Industries CLD, Industry Nine 1/1 and SOLiX, Chris King R45 and Hope RS4 hubs, usually with Sapim CX-Ray, CX-Sprint or D-Light spokes or DT Aerolite and Competition, and brass nipples.
Tire range on the Serpentine X is 35 to 45mm. Pick gravel or all-road as your bike type in the configurator and it recommends a spoke count and lacing pattern.
Build a wheel around it
Offered for gravel and road disc, tandem and e-bike, mountain bike, MTB single-speed and fat bike builds in our Custom Wheel Program. Start with the Astral Serpentine X Carbon Rim and the configurator pins it for you, then checks each choice you make against it.
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.
How Astral tests its rims
Astral Cycling is the rim brand of Rolf Prima; both operate from one facility in Eugene, Oregon, where Rolf Prima states alloy rim production has been in-house since 2014. Astral joins alloy rims with a press-fit sleeve about 2.5 inches long weighing 4-5 g that doubles the wall thickness at the joint, avoiding the heat-affected zone of welding. All wheels are hand-built in Eugene. Rolf Prima states it does not farm out testing and has logged "over 10,000 hours of lab testing to above industry standards."
Warranty: Astral states alloy rims are covered two years and carbon rims five years for the original owner, excluding impact damage; Rolf Prima wheels (2016 and newer) carry five years, bearings two years, plus lifetime discounted crash replacement for registered wheels.
Astral's videos
From Astral
Certifications
- Made in USA (alloy rims and wheels) — Astral and Rolf Prima state alloy rims are rolled and all wheels hand-built in their Eugene, Oregon facility; rim production in-house since 2014 (source)
- ISO 4210 base + in-house standard — Fatigue drum at 47 mph vs ISO 15 mph, life requirement 66% above ISO; UCI 40 J impact plus higher in-house level; ISO 4210 dry/wet brake tests (source)
- UCI note — Rolf Prima FAQ: Aspin and Elan family are 'Standard' wheels not requiring UCI approval; no approved-model list verified (source)
- Rolf Prima Certainty — In-house engineering and testing lab, eleven patents, over 10,000 hours of lab testing, 5-year warranty, lifetime crash replacement (source)
Sources on Astral's site:
- Testing – Astral Cycling
- FAQ's – Astral Cycling
- Astral Rim Warranty – Astral Cycling
- Technology – Astral Cycling
- Rim Joining: The Process and the Mystery – Astral Cycling
Astral publishes those results; ProWheelBuilder builds the rim into a wheel and does not test it in a lab.
Building it at ProWheelBuilder
Astral makes the Serpentine X; ProWheelBuilder is an independent wheel builder in Georgia, not the manufacturer. Spokes are cut from the ERD we measure on the actual rim, the wheel comes up in stages on a tensiometer, and it is stress-relieved and trued before it goes in the box; tape and a valve go on if you ask.
The configurator filters to what fits, crosses out what is not made, and prices the build as you go.
Warranty
Manufacturer's warranty. Rolf Prima gives a one-year limited warranty on its wheels under normal use. Astral is Rolf Prima's rim brand; ask us and we will confirm the current terms for the exact rim before you buy.
ProWheelBuilder. Built into a wheel by us, this part is covered by our own one-year wheel warranty on top of the maker's. For a year we replace broken spokes whatever caused them, and we cover the labor on the wheel - truing, re-tensioning, a rebuild if it needs one. If a rim or hub fails and its maker covers it, we run that claim for you; if the maker says no, you get an eligible replacement rim or hub at 25% off retail. You pay the shipping each way. Wheels built from parts you send us are excluded.
Full terms are on our Policies & Warranty page.
Serpentine X Carbon Rim questions
What tire width suits this rim?
At 30mm inside this is a trail width, sized around 2.1 to 2.4in tires. That is wide enough to stop a modern trail casing rolling under you in a corner without pushing the tread so flat that it wears down the middle.
Which spokes and nipples suit the Serpentine X?
For most riders a double-butted spoke such as Sapim Race or DT Competition with brass nipples; lighter riders can go to Sapim Laser or CX-Ray. The configurator recommends a gauge and count for the Serpentine X from your bike type and weight.
Serpentine or Serpentine X?
Serpentine for 28 to 38mm tires and road-first riding; Serpentine X for 35 to 45mm tires and gravel-first riding, with its wider bed.
Is the Serpentine tubeless?
Yes. Astral's Tubeless Easy bead seats a tubeless tire with a floor pump; we tape and fit a valve on request.
What tires fit the Serpentine?
28 to 42mm. A 32mm road tire or a 38mm gravel tire is the usual pairing.
Who is Astral?
The rim brand of Rolf Prima, the wheel company in Eugene, Oregon.
Is ProWheelBuilder the manufacturer of the Astral Serpentine X Carbon Rim?
We are not. Astral manufactures the rim; ProWheelBuilder's part is the wheel: measuring, lacing, tensioning and truing it here in Georgia.
Not sure? 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.
