Flyxii FR-216 Monstercross gravel-killer 29er build

This is my first experiment purchasing a bicycle frame directly from China. This is a Flyxii FR-216 29er frame with matching fork. I purchased this frame directly from Flyxii via Aliexpress with the intent of building a drop-bar monstercross  29er rig for really rough gravel events, such as Gold Rush in South Dakota. Complete, the build weighs in at 23.5 lbs, easily 3 lbs lighter than my 700c Soma Double Cross Disc gravel bike.

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Level-set time: this is the first carbon-fiber bicycle I’ve ever built, and the first I’ve ever owned. All of my previous rides have been steel. I learned a lot during this build, in no particular order:

  • Tubeless tire casings ooze a lot of sealant. Really.
  • Setting up tubeless doesn’t work when you keep overinflating the tires. Don’t exceed 40 psi.
  • Full-length brake housing is required on frames like this. They don’t come with instructions, so you have to work that out for yourself.
  • All threads need to be chased, so you need a bottom bracket thread and facing tool, as well as 10mm and 4mm taps. Be really careful, all of these threads are aluminum!
  • Use a torque wrench everywhere, torque keys are cheap and easy to find, and the pre-set 5Nm ones are brain-dead easy to use.

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The bike is SRAM X7, with Apex shifters, BB7R brakes, and an X9 front derailleur. A Salsa Promoto stem and Salsa Woodchipper bars, along with a Flyxii carbon seatpost, Salsa Lip-lock,  a Fizik Aliante VSX saddle, and Shimano XT SPD pedals form the cockpit. Of particular note, I installed 40/27 Rotor Q rings on SRAM X7 crank. I think they are much kinder on my knees than round rings are. Wheels are WTB i23 rims, Deore XT 6-bolt disc hubs with 160mm rotors and WTB Nano TCS tires setup tubeless. It took two layers of Stan’s tape, and 3 oz of sealant to get the setup to work, they’ve held air now for 3 weeks.

On this particular frame, the seat tube is 34.9mm, the seatpost is 31.6mm, and it takes an IS type headset and BSA bottom bracket.

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It’s cold as fuck here right now, so a full test ride will have to wait for temps warmer than 15F.

One thought on “Flyxii FR-216 Monstercross gravel-killer 29er build

  1. Andrew Triggs March 21, 2017 / 11:13 am

    Awesome. I have the same exact idea. I want to build something that would be on par with the Salsa Cutthroat. I hope yours is awesome/

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