Co-Motion CX Rex 56cm w/Rival 1 Hydro

Availability: In stock (1)

The CX Rex is a light aluminum disc brake-equipped ’cross bike, which would be the choice for a podium chance when racing in varied conditions.

Why aluminum? Co-Motion has worked with aluminum alloys for the past 25 years and can utilize its wealth of experience in building with new aluminum alloys in customized tube parameters to yield the best ride qualities for a bike’s designed application. Brian Cannon of Co-Motion explains, “Aluminum tubing has come a long way since the beginning, with advances like custom butting profiles and proprietary heat-treating cycles, for example. It’s a great material to work with and very applicable to race bikes. The aluminum frames we are building today are much lighter and more comfortable than produced in the past, comparable to high-end carbon frames.”

It’s not just them: Two other high profile companies, Trek and Van Dessel, have turned to aluminum for high-end cyclocross race bikes, fueling the aluminum renaissance. In the end, the manner of how the material is used is at least as important as what the material is.


The Frame

The frame is made using a 7005 series aluminum alloy they call ACMUltra7, a custom 7005 series aluminum alloy, with tubes drawn and butted to Co-Motion’s specifications. After welding, the frame is heat-treated by Co-Motion for strength and durability. The tubes are dimensionally “oversized” by standards even of aluminum frames of a decade ago. The down tube alone is 51.2mm in diameter, about the size of a small energy drink can.

Though the tubes are all of unusually large diameter, they are all round, and the only externally shaped tube is the tapered head tube. The frame is designed in a semi-compact style with a 6-degree sloping head tube, a 52cm seat tube (measured center-to-top) paired with a 56cm effective top tube. With a stretched out front center and chainstays just a fraction over 43cm, the CX Rex has a wheelbase that is a on the longer side at 103cm, and toe overlap is consequently minimal. The long, curved dropouts, which include the rear IS disc caliper mount, contribute to the chainstay length and add an iconic look to the rear triangle.

The bridged chainstays are ovalized, bent, and indented around the tire and combined with the additional length, offer good tire clearance. Frame angles are a typical 72-degrees for the head tube and 74-degrees for the seat tube.

Frame: Optimally-profiled ACMUltra7 zonally-butted 7005 Aluminum tubing
Fork: ENVE CX cyclocross fork
Crankset: SRAM Rival 1 Crankset - 175mm, 10/11-Speed, 42t, 110 BCD, GXP Spindle Interface, Black
Derailleur Front: n.a.
Derailleur Rear: SRAM Rear Derailleur Rival 1 Type 3.0 Long Cage 11s Black
Cassette: Sram PG1130 11-42 11s NX Black
Shifters: SRAM Rival 22 DoubleTap Lever Set
Brakes: Sram Rival Hydro, w/160mm rotors
Wheels/Rims: Rolf Prima Hyalite
Tires: Schwalbe G-One Speed 700x35c
Handlebar: Zipp
Stem: Zipp Service Course
Saddle: Selle Italia XR
Seatpost: Co-Motion
Color: Gloss Black w/ Orange accents
0 stars based on 0 reviews
Check out Cycle Quest on Yelp