Astral Outback Aluminum Rim
The Astral Outback is the carbon gravel rim from Astral, the rim brand of Rolf Prima in Eugene, Oregon: a wide inner bed for 38 to 50mm tires, Astral's Tubeless Easy bead, and a carbon layup with extra material at the bead and spoke bed that makes it the tough, light gravel and adventure rim in the Astral range. It is the carbon version of the Wanderlust for riders who want the weight saving and the damping of carbon on rough gravel.
This page covers the Astral Outback Aluminum Rim in 29in, 27.5in, 20in. The Outback 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 Wanderlust is a welded double-wall aluminum rim with a 24mm-class inner bed that gives a 42mm gravel tire a square, stable shape at low pressure, a Tubeless Easy bead shelf that seats and holds a tubeless tire without drama, and spoke holes angled toward the hub flanges so the nipples sit straight and the wheel builds to even tension. The section is deep enough to be stiff under a loaded bike and the walls are thick where rock strikes land. Standard nipples, J-bend spokes, disc only.
How it rides
An Outback wheel is light, quick and forgiving on rough gravel. The carbon rim takes the sting out of washboard, the wide bed keeps a 45mm tire stable at low pressure, and the reinforced bead shrugs off the rocks that dent alloy gravel rims. It is the Astral rim for gravel racing and fast adventure riding; for a lower price the alloy Wanderlust is the same profile.
Specifications
| Wheel size | 29in, 27.5in, 20in |
|---|---|
| ERD | 596 (29in), 558.3 (27.5in) |
| Inner width | 25 mm |
| Depth | 23 mm |
| Drillings | 28h, 32h, 36h |
| Weight | 460g (700c/29in), 430g (650b/27.5in), 280g (20in) |
| Material | Aluminum |
| Tire type | Clincher Tubeless Compatible |
| Brake | Disc |
| Profile | Triangle |
| Spoke bed | Offset 2.5 mm |
| Nipples | External |
| Finishes | black |
This version
This version is the Outback in 29in, 27.5in, 20in, drilled 28h, 32h, 36h, about 460g, 25mm inside, 23mm deep, disc. Where the same rim is sold in another size or brake type, that is a separate listing with its own page.
This is the disc-brake Outback: plain sidewalls, no brake track to wear, a touch lighter. It fits any disc-brake bike and it is the version most of our customers now build; the rim-brake version is a separate listing.
Sizes, fit and compatibility
The Astral Outback Aluminum Rim comes in 29in, 27.5in, 20in and 28h, 32h, 36h drilling. It is a disc-brake rim. We build the Outback 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, D-Light or Race spokes or DT Aerolite and Competition, and brass nipples.
Tire range on the Outback is 38 to 50mm. Pick gravel or bikepacking 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, mountain bike and MTB single-speed builds in our Custom Wheel Program. Start with the Astral Outback Aluminum 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."
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
Everything in this section is published by Astral. ProWheelBuilder is the wheel builder, not the tester, and the rim reaches us as the maker ships it.
Building it at ProWheelBuilder
Astral makes the Outback; 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. Our one-year wheel warranty applies to any wheel we build around this part, alongside whatever the manufacturer offers. Inside that year, broken spokes are replaced no matter how they broke, and the wheel labor is ours - truing, re-tensioning or a full rebuild. A rim or hub failure that the maker covers, we claim for you and see through; one the maker declines, we answer with an eligible replacement at 25% off current retail. Shipping both ways is yours, and components you supply yourself fall outside this cover.
Full terms are on our Policies & Warranty page.
Outback Aluminum Rim questions
What tire width suits this rim?
25mm inside is the all-road and gravel width. Think 32 to 45mm tires: wide enough to support a gravel casing properly so it holds its shape at low pressure, narrow enough that a 30mm road tire still sits right if you swap wheels between bikes.
Which spokes and nipples suit the Outback?
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 Outback from your bike type and weight.
Is the Wanderlust 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 Wanderlust?
38 to 50mm. A 42 to 45mm gravel tire is the usual pairing.
Wanderlust or Outback?
Wanderlust is the alloy gravel rim; Outback is Astral's carbon gravel rim, lighter and stiffer at a higher price.
Who is Astral?
The rim brand of Rolf Prima, the wheel company in Eugene, Oregon; Astral rims are designed by wheel builders for wheel builders.
Is ProWheelBuilder the manufacturer of the Astral Outback Aluminum Rim?
No. The rim is made by Astral; we are the wheel builder in Georgia who laces it into a finished wheel to your spec and stands behind the build.
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.
