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FX Tracklocross Frameset
FX Tracklocross Frameset

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Bike Description & Terrain

The FX is the product of wanting to shred around on dirt with our brakeless fixed-gear frames. We tweaked specific areas of the bike to try to improve common issues that you encounter riding fixed and especially, riding fixed on dirt.

The Poseidon FX has a raised bottom bracket that prevents pedal striking even on the steepest of drops. The head tube angle is slacked so your toe doesn't hit the front tire as easily when turning. This also offers a slightly softer ride on rougher terrain. On the small frame in particular you will see that the head tube angle is slacked the most as toe overlap is a common problem for smaller frames. You can pedal freely even through the tightest of turns on that size.

The FX frame can easily fit a set of 700x40 cross or gravel tires. 

The fork can clear a Tektro R559 Long Reach Rim Caliper.

Frameset includes Frame, Headset, Seatpost Collar, and Fork only.

International Customer? 

Find out about international shipping here:

Box Dimensions are: 39x7x22 (inches)

Box Weight: 10.5lbs


We made this bike to fit your standard fixed gear wheels so a 100mm front and a 120mm rear.

Fits a 68 x 115 square taper bottom bracket. We recommend a square taper bottom bracket and crankset for this build.

All straight returns are subject to a 15% restocking fee and return shipping. The bicycle must be returned in the original packaging (unopened and unridden).

Fixed Gear from Road to Trail

Fixed Gear from Road to Trail

Sizing Specifications

Full Specifications


Aluminum (Lifetime Warranty). Uses an EC 34 Headset.

Seat Post

Fits 27.2




5lbs with uncut steerer.

Handlebars and Stem
Brake Levers
Rear Derailleur
Bottle Cage Boss

2 Available

Disc Rotor
Bottom Bracket

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Customer Reviews

Based on 20 reviews
Julius Porter
Great quality affordable frame!

Light weight simple design! I'm very happy with this frame-I went with the polished chrome look and it's beautiful!
Quality control was great for me, everything came as it was supposed to. I had everything I needed to start my build.
It's a solid frame and makes for a smooth ride. I ride brakeless and i'm generally commuting on the street,
but occasionally I hit trails and it's just as nimble and fun to ride.

Jason Prudhom
Love my Poseidon fx

Ordered the frame around Christmas. Got it quick but noticed the rear track ends looked a little goofy. Send an email asking about it and customer service told me to send it back in and they’d send a different one. Replacement was a week and a half to me and looked better than the first. Built up smooth and easy. Went with 650b x 2.1 panaracer sk’s (they fit, but not much clearance in the back. Downsized to a 1.9). Bike is awesome. Customer service was awesome. Love bikes with a low barrier to entry/high fun ratio!

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About Poseidon Bikes
Dedicated to Quality & Affordable Adventures
Building The Highest-Value Bikes In-House

Discovery doesn't need to be unattainable and Exploration should be something right out your door. We produce our bicycles in a factory we own and operate to ensure you have an affordable price. We're Breaking the Barrier to Discovery and Adventure so you can experience what so many others have done before us.