Chromag Phase30 Rim
The Chromag Phase30 is a 30mm-wide aluminum mountain bike rim for aggressive trail and all-mountain riding: tubeless ready, disc brake only, 32 hole, and 584 grams in 29in or 545 grams in 27.5in. It is the lighter sibling of Chromag's BA30, built to climb and change direction more easily while keeping the thick bead wall the BA30 is known for.
This page covers the Phase30 in both wheel sizes, in black. It is built to order here: choose the hub, spokes and nipples in the configurator, and we lace, tension and true the wheel by hand in Georgia.
Design and construction
Chromag designs its parts in Whistler, British Columbia, and the Phase30 is shaped around one idea: a rim that shrugs off rock strikes. The bead wall is roughly twice as wide as most rims and its outer edge has an extra-large radius, so a hard hit is spread over more metal and is less likely to cut the tire sidewall or dent the hook.
Inside, an internal bracing profile stiffens the 17mm-deep section without making it tall. The seam is fusion welded and then ground smooth, which Chromag says makes the joint stronger than any other part of the rim, and the spoke bed is angled toward each spoke so the spoke and nipple sit straight instead of bending at the thread. It takes standard external nipples and J-bend or straight-pull spokes, whichever the hub calls for.
How it rides
At 30mm inside, the Phase30 gives a 2.4 to 2.6in trail tire a well supported, square profile, so it can run lower pressure for grip without folding in hard corners. The shallow 17mm profile keeps some vertical give, which takes the sting out of square-edge hits on a hardtail or a mid-travel trail bike.
Pick the Phase30 when weight matters a little more than outright toughness: long climbs, trail riding with some rough descents, or a lighter front wheel paired with a BA30 V2 at the back.
Specifications
| Wheel sizes | 29in (622), 27.5in (584) |
|---|---|
| ERD | 604 mm (29in), 566 mm (27.5in) |
| Weight | 584 g (29in), 545 g (27.5in) |
| Inner width | 30 mm |
| Outer width | 35 mm |
| Depth | 17 mm |
| Drilling | 32 hole |
| Tire type | Clincher, tubeless ready, hooked bead |
| Max tire pressure | 45 psi with a 2.4in tire, 30 psi with a 2.8in tire |
| Max spoke tension | 125 kgf |
| Valve | Presta |
| Brake | Disc only |
| Material | Premium extruded aluminum, fusion welded and ground seam |
| Nipples | External |
| Finish | Black |
Which version this is
What this listing covers: the Phase30 in 29in and 27.5in, 32 hole, black, chosen in the configurator.
The Phase30 is Chromag's trail rim. For enduro racing, bike park laps and the heaviest hits, the BA30 V2 uses the same 30mm width in a taller, 19mm reinforced section and is the stronger of the two.
Sizes, fit and compatibility
The ERD changes with the diameter, so we cut spokes for the size you choose: 604mm in 29in and 566mm in 27.5in. Both sizes fit modern trail and all-mountain frames, including mixed-wheel bikes with a 29in front and a 27.5in rear.
We build it on 32 hole Boost and standard-spacing disc hubs, 6-bolt or Centerlock, usually with Sapim Race or Leader spokes and brass nipples for the strength a mountain wheel needs. Choose mountain bike, e-bike or fat and plus bike as the bike type, and the configurator recommends a lacing pattern.
Build it with us
We build this rim to order. Open the Custom Wheel Program with the Chromag Phase30 Rim already selected and pick the parts around it; it is offered for tandem and e-bike, mountain bike, MTB single-speed and fat bike builds, and the configurator will not let you assemble a combination we would not build.
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.
Chromag's specifications and limits
Chromag designs and rides its products in the Coast Mountains of British Columbia and publishes these limits for the Phase30: 125 kgf maximum spoke tension, 45 psi maximum with a 2.4in tire and 30 psi with a 2.8in tire, plus the ERD and weight of each size. It does not publish impact or fatigue test results, so ask us if you need a figure confirmed. Chromag covers its components, rims included, for two years against defects in materials and workmanship.
Sources on Chromag's site:
The figures above are Chromag's own. ProWheelBuilder does not run these tests; our part is the wheel we build on the rim.
Building it at ProWheelBuilder
Chromag makes the Phase30; ProWheelBuilder is an independent wheel builder in Georgia, not the manufacturer. Each wheel is built the same way: spokes cut to length for your size from Chromag's ERD, staged tensioning with a gauge and kept under Chromag's 125 kgf limit, stress relief and a final true, with tubeless tape on request.
The configurator shows only hubs and spokes that match the 32 hole Phase30, strikes through anything that is out of stock, and prices the wheel live.
Warranty
Chromag's warranty. Chromag warrants its components, its rims among them, against defects in materials and workmanship for two years from first purchase, to the original owner; the warranty is not transferable. Normal wear, corrosion, crash damage, improper installation and lack of maintenance are not covered, though Chromag assesses crash damage case by case and may offer a crash-replacement discount.
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.
Phase30 Rim questions
What tires suit the Phase30?
Chromag designs it around 2.4 to 2.6in trail tires and lists pressure limits for tires up to 2.8in.
Is the Phase30 tubeless?
Yes, it is tubeless ready. Choose tubeless tape in the configurator and use a tubeless-ready tire.
Phase30 or BA30 V2?
Both are 30mm inside. The Phase30 is lighter (584g in 29in) and suits trail and all-mountain riding; the BA30 V2 is taller and reinforced for enduro and downhill, at 640g.
Which drilling is it?
32 hole, the drilling Chromag makes in both sizes.
Can I use rim brakes?
No. The Phase30 is disc only.
Is ProWheelBuilder the manufacturer?
No. Chromag makes the rim. ProWheelBuilder is an independent custom wheel builder in Georgia that builds it into a wheel to your spec.
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.
