I had an Axiom Journey rack on my mech bike for years. Excellent rack.
The Como does come with frame inserts to accept rack arms so no issues there.
However, the frame bolts that would normally attach the rack's main struts are threaded into the struts of my Racktime rack on the inside surface of the frame on my Vado. From Specialized's pics it appears to be the same for the Como; the fenders are attached with small brackets on the inside surface of the frame. Looks like you'd need to lose the rear fender.
Not the best pic, but I think you can make out the cone on the rack strut that mates with an indent in the Vado frame. If the Como is like this as well there may be an issue with a solid attachment of the Axiom's smooth struts over the frame indent. I'd suggest you take a look on your bike or ask your LBS about this.
My Axiom rack doesn't have threaded holes on the main struts. I assume they're still like this. If so, you'd need to provide a bolt, nut, and washer to attach the struts. Be sure to use 'blue' threadlock on these bolts.
The spacing between the frame arms measures ~150mm on my Vado. I assume it's the same on a Como as they have the same through axle length. The Axion site dimensions the inside clearance between the struts as 145mm. Can't say for sure what the outside dimension is but you would probably need to squeeze the struts together to fit the Como frame, but it should fit OK after a bit of force.
I know, more questions than answers, but hopefully this post helps identify issues you can address before buying the rack. The other approach that others have used is to buy the product with free Amazon returns. If it doen't work out, return it for a refund...
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