A Niner Jet 9 RDO with the drivetrain, brakes, and wheels upgraded over the stock build — SRAM GX Transmission AXS, Shimano SLX 4-piston brakes, Race Face Arc 27 XC wheels, Maxxis Rekon front and rear. A better bike for the money than buying up the lineup.
Stock vs. Custom
- Fox Float rear shock
- Fox 34 Rhythm fork
- Niner OEM wheels
- Maxxis DHF front / Rekon rear
- SRAM SX Eagle 12-speed
- SRAM Level brakes
- KS LEV Si dropper
- Race Face Affect R bar & stem
- Fox Float rear shock — retained
- Fox 34 Rhythm fork — retained
- Race Face Arc 27 XC wheels
- Maxxis Rekon front and rear
- SRAM GX Transmission AXS 12-speed
- Shimano SLX 4-piston brakes
- KS LEV Si dropper — retained
- Race Face Affect bar & stem — retained
Why This Build
The Gap in the Lineup
The stock Jet at this level comes with Fox Rhythm suspension and a SRAM SX Eagle drivetrain — good suspension, entry-level drivetrain and wheels. The next step up the lineup jumps to Fox Factory with Kashima, SRAM GX, and DT Swiss or Stan’s wheels. The whole bike upgrades at once, and the price reflects that. The problem is that a lot of riders want better shifting but don’t need the factory suspension upgrade. This build captures that.
The stock Niner suspension has actually held up well in our experience — nobody’s had problems with it, and not everyone is tuning their fork and shock anyway. The drivetrain is where the real gap is — the SX is an entry-level system and you feel it in the shifter. SRAM GX Transmission is a completely different experience.
SRAM GX Transmission AXS
The Transmission drive system — the direct-mount derailleur that eliminates the b-knuckle and cage pivot — shifts under full load. It’s been on the shop’s bikes for a season and a half and the durability has been excellent. For the Jet’s intended use (local XC trails with some all-around trail riding), GX Transmission is the right call, and the wireless AXS shifting adds to that.
Wheels & Tires
The stock setup ran a heavier front tire — more tire than this bike needs for how most Jet riders use it: roughly 80% local XC, with enough versatility for some trail. The build went to Race Face Arc 27 wheels, a lighter XC hoop rather than a heavy all-mountain wheel, with Maxxis Rekon front and rear to match the bike’s actual job.
Shimano SLX Brakes
This is a Shimano/SRAM mix — which works fine on a wireless AXS system since there’s no cable interaction. The SLX 4-piston brakes are among the best-feeling brakes at this price, and some riders strongly prefer the Shimano lever feel over SRAM. This build accommodates that; if someone wanted SRAM brakes instead, that’s an easy swap to spec.
Come into the shop and you’ll often see bikes on the rack with wheels and a cockpit but no drivetrain or brakes yet — those are waiting for a rider to pick exactly what they want. Building here gives us that freedom.
Best bang for the buck on the Jet platform
This is the question that started the whole Bikes We Build series: given a budget, what’s the best bike you could actually put together? On the Jet, the answer is to keep the OEM Fox suspension and cockpit — which hold up fine — and spend where it’s felt: GX Transmission shifting, SLX brakes, and a lighter Arc 27 XC wheel. It lands around the cost of buying up the lineup, but with the better drivetrain and brakes.
Want a Custom MTB Build?
If the stock build isn’t quite right, come in or reach out. We’ll spec something that makes more sense for what you’re trying to ride.