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Prototype - Evolving Daily

Project 321 G3 rear hub (148x12 Boost, XDR) Rear Hub

What the checker says65will not fit

Run variant by variant through the mountain bike builder’s own engine. Every sentence below is the checker’s, unedited. Nothing here says this part fits your bike; it says what it does and does not fit among the parts we hold.

Checked against 6050 verified mountain bike parts in this catalog. 5895 produced no finding of any kind.

Will not fit

  • Will not fiterror · Rear RotorRear rotor interface mismatch: Center Lock rotor on 6-bolt rear hub - no adapter exists for this direction. On 65 of the 177 verified rotors in this catalog.
  • Will not fiterror · FrameRear axle mismatch: Frame is SuperBoost 157x12 but Rear wheel hub is Boost 148x12. On 21 of the 258 verified frames in this catalog.
  • Will not fiterror · FrameRear axle mismatch: Frame is 135x5-qr but Rear wheel hub is Boost 148x12. On 5 of the 258 verified frames in this catalog.
  • Will not fiterror · FrameRear axle mismatch: Frame is 10x135 bolt-on but Rear wheel hub is Boost 148x12. On 2 of the 258 verified frames in this catalog.
  • Will not fiterror · FrameRear axle mismatch: Frame is 150x12 (DH, pre-Boost) but Rear wheel hub is Boost 148x12. On 2 of the 258 verified frames in this catalog.

Freehub, Cassette. 60 more findings from the same check, on up to 1 of the 60 verified cassettes each.

Open a variant in the builder to see the ones that apply to your own parts.

The checker compares the dimensions listed in what we check, and what we don’t. “No conflicts found” means no conflict among those dimensions — not a guarantee that a build works. Errors mean it won’t fit; warnings mean it works but check; infos are notes.

$440.00 MSRP·312 g

What the maker states

Freehub
/ driver SRAM XDR
Rotor mount
6-bolt
Hub
Spacing Boost 148x12
The rest of what the maker states1 not published

1 further field the checker looks for is not published by Project 321, so we leave it blank rather than estimate it, and that check stays silent on this rear hub. It is maximum system weight. Each is recorded as “not stated by the maker (not checked)”.

Source: the maker’s page. Last checked 2026-07-24.

Checked against

The checker ran this model against every verified part below that it has a slot for, the same way it checks a build in the builder. What follows is the verdict it actually produced for that specific pairing — not a recommendation, and not a guarantee any of these parts fits your own bike.

6 of 1879 counterparts with a page of their own that the checker actually probed this model against, in alphabetical order by brand and model — never by price, popularity or the verdict itself.

Where this sits

All Project 321 rear hubsOpen a variant in the builder to see the ones that apply to your own parts