Bike Review: The Poseidon X Gravel Bike
Updated: Oct 20, 2021
I bought a Poseidon X a few months back, and have been using it to tear up trails and roads all over the country. It's been on everything from pavement to crushed gravel to dirt, and even some rough and gnarly singletrack. Having just hit 300 miles, I think it's time for a review.
The bike is a dropbar configuration Poseidon X, in Interstellar Blue - I am 6’0” and the large fits great. I have made three upgrades: swapping out the Poseidon-branded stem for a slightly longer and shallower carbon stem, replacing the tires with 35mm Panaracer Gravel Kings (they’re faster on pavement with knobby edges for cornering, and they look sick), and replacing the stock seat clamp with a quick-release seat clamp.

Here are the specs from the Poseidon website:
Frame: 6061 Double Butted Hydroformed Aluminum
Fork: Full Carbon fork – Tapered 1 1/8" – 1 1/2"
Shifters: MicroShift Advent X 10 Speed
Handlebars: Poseidon Adventure Bars: 31.8 diameter. 46cm wide. 24° flare
Brake Levers: MicroShift Advent X
Rear Derailleur: MicroShift Advent X 10 Speed with Clutch
Brakes: Tektro MD-C510 Mechanical Disc
Disc Rotor: Tektro 160mm F&R
Crank: Prowheel 38t Narrow Wide Chainring with 170mm crank arms
Chain: KMC 10 Speed
Bottom Bracket: 68mm English Threaded Square Taper
Cassette: Microshift 11-48T Advent X 10 Speed
Seat Post: Promax Alloy 27.2
Saddle: Poseidon X alloy rails
Pedals: Platform Pedals
Tires: Kenda Small Block 700x35. Bike can handle up to a 700x40 tire with clearance for mud. 650b compatible with up to a 1.9" wide tire.
Wheels: Poseidon Alloy 700c 32h, quick release axle.
You will find multiple locations on the frame to mount an assortment of accessories in the front and rear
Bottle Cage Boss: 3 on the size Small, 4 on sizes M, L, and X
Price: $749.99
Let’s start with the frame. The full carbon fork makes a big difference - the Poseidon X is noticeably lighter than a full aluminum gravel bike, and the aluminum frame is obviously much cheaper than a carbon bike. I’ve crashed it several times (oops), and it has held up very well. There are tons of attachment points, and I’ve easily been able to bring along everything I need for my rides. Once I take it bikepacking, I’ll be able to take all of my gear along no problem. The internal cable routing is nice, since it keeps the cables away from my frame bag. The chainstays are a bit wide and I bump them with my heel sometimes, which can be annoying on long rides.

The Microshift Advent X drivetrain provides a huge gearing range. The 48t gear has gotten me through some tough climbs, and the 11t has let me bomb the descents. I also like that Microshift utilizes a button to shift into higher gear, rather than the standard of pulling the brake lever inward. The 1x setup is easy to maintain, and shifting requires little thought - I highly prefer it to a 2x or 3x setup. The gear spacing is a little big, and sometimes it’s hard to lock in a cadence; such is the compromise with a 1x10 drivetrain with such a large range. Also, I sometimes find that I can’t get into a high enough gear to pedal through my descent. It usually tops out around 36 mph on pavement. Swapping in a bigger chainring is an easy fix for that, if you can take the climbs being a little tougher.
The 46cm wide dropbars are too wide for my liking, and get uncomfortable during longer rides. While I like the flared dropbars, I would prefer a shallower angle since I mainly use the drops for descents, and it’s hard to be aerodynamic with your arms that wide.

The disc brakes provide great stopping power in any weather and terrain. Disc brakes are a little bit heavier, and more difficult to adjust and maintain, but the performance is much better. Plus, they don’t wear down your wheel like rim brakes do.
The saddle is Poseidon-branded, and I have found it very comfortable. It was the first thing I planned to swap out, but I actually decided to keep it on because I like it so much. The wheels are not tubeless compatible - you will have to get new wheels if you want to go tubeless. The seatpost and pedals both do a fine job, and are easy to swap out if you decide to upgrade. One last nitpick - the seat clamp that comes with the bike does not have a quick-release - I easily swapped it out for one that does, so I can adjust my saddle height on the fly. In fact, one of the strengths of the Poseidon X is that the compromises are in all the right places - with components that are easy to upgrade.
Lastly, the cost. At $749.99, the price that Poseidon is offering this bike at is INSANE! The only quality gravel bike that’s anywhere close is State Bicycle Co.’s 4130 All-Road, and that costs $899.99. Poseidon has made a quality bike here, and is providing it for a great price. If the bike is out of stock (it usually is), check the Poseidon Bike Instagram page - they usually announce new stock there first.
Pros:
Very affordable
Solid, light frame
Wide tire clearance
Huge gearing range
Easy to upgrade
Cons:
Heavier than a carbon frame
Large gear spacing, could use a higher gear
Handlebars too wide
Not tubeless compatible
Chainstays too wide
Recommended upgrades:
If you are going to make upgrades, I recommend the following:
Quick release seat clamp - adjust your saddle height on the fly, without needing an Allen key.
Carbon stem - lighter and better vibration dampening.
Carbon seatpost - again, lighter and better vibration dampening.
Clipless pedals - better pedaling efficiency and power, especially for long rides.
Wheels & tires - a tubeless-compatible wheelset and tubeless tires will reduce the risk of flats, and allow you to ride at lower pressures for improved traction and comfort.