Astral Serpentine Aluminum Rim
The Astral Serpentine is the carbon all-road rim from Astral, the rim brand of Rolf Prima in Eugene, Oregon: a modern wide bed for 28 to 42mm tires, a moderate depth that balances aero and comfort, Astral's Tubeless Easy bead and a carbon layup tuned for the road-to-gravel riding most drop-bar bikes do now. It is the carbon rim we build for endurance road, all-road and light-gravel bikes that want one wheelset for everything.
This page covers the Astral Serpentine Aluminum Rim in 29in. The Serpentine comes from us only as a finished wheel: pick the hub, spokes and nipples, and we lace, tension and true it by hand in Georgia before it ships.
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 wheelset is fast on the road, calm in a crosswind and comfortable on gravel with a 35mm tire. It is the rim for the rider who does a road race on Saturday and a gravel ride on Sunday on the same bike. For wider tires the Serpentine X is the better bed; for pure gravel the Outback.
Specifications
| Wheel size | 29in |
|---|---|
| ERD | 600 (29in) |
| Inner width | 32 mm |
| Depth | 20 mm |
| Drillings | 28h, 32h |
| Weight | 580g (700c/29in) |
| Material | Aluminum |
| Tire type | Clincher Tubeless Compatible |
| Brake | Disc |
| Profile | Triangle |
| Nipples | External |
| Finishes | black |
About this listing
Version notes. 29in, 28h, 32h, about 580g, 32mm inside, 20mm deep, disc. The other sizes and brake versions of the Serpentine have their own listings; this page is for this one.
The disc version of the Serpentine 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 Aluminum Rim comes in 29in and 28h, 32h drilling. It is a disc-brake rim. We build the Serpentine 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 or CX-Sprint spokes or DT Aerolite, and brass or alloy nipples.
Tire range on the Serpentine is 28 to 42mm. Pick road, all-road or gravel as your bike type in the configurator and it recommends a spoke count and lacing pattern.
Build it into a wheel
This rim is live in our Custom Wheel Program for mountain bike, MTB single-speed and fat bike builds. Start a build with the Astral Serpentine Aluminum Rim and the configurator opens with this exact rim pinned at the top of the Astral / Rolf list — you choose the rest of the parts and it validates every combination as you go.
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.
Testing, standards and warranty at Astral
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."
Astral and Rolf state they use ISO 4210 "as a base starting point but it is not tough enough." Their drum fatigue tester runs at 47 mph against the ISO 15 mph, putting over 3 times the energy into the wheel, with a life requirement 66% higher than ISO. Impact tests use a calibrated steel anvil to the UCI 40 J standard and then a higher in-house level, at spokes, between spokes and at the valve hole, including pre-heated rims. Rolf's carbon brake protocol runs ISO 4210 dry and wet tests, 300 W for 15 minutes twice, 400 W for 16 minutes twice, 450 W and 500 W for 16 minutes, and 500 W for 3 minutes followed by the UCI impact test with no failure allowed. No rider weight limit is stated.
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
The figures, certificates and media above are Astral's own. ProWheelBuilder does not run these tests; our part is the wheel we build on the rim.
Building it at ProWheelBuilder
Astral makes the Serpentine; ProWheelBuilder is an independent wheel builder in Georgia, not the manufacturer. We measure the rim before we cut a spoke, bring the wheel up in three or four rounds with a gauge, stress-relieve it between rounds and true it last, then tape it and fit a valve if you want it tubeless.
Only compatible hubs and spokes appear in the configurator, impossible combinations are struck through rather than hidden, and the price is live.
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. 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.
Serpentine Aluminum Rim questions
What tire width suits this rim?
32mm inside is an enduro width, meant for 2.3 to 2.6in tires. It gives a big casing a square, supported profile so you can drop pressure for grip without the tire folding, which is the whole point of a rim this wide.
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 it tubeless-ready?
Yes. Astral lists the Serpentine Aluminum Rim as clincher tubeless compatible; we tape and fit a valve when you choose the tubeless option.
Which spoke count should I choose?
It depends on your weight, terrain and the hub, not the rim alone. The configurator recommends a count from your bike type and rider weight, within the drillings this rim is made in.
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.
