Axiom seat Collar
Rating: 
Reviewed By: Jeff on 3/8/16
Worked perfectly. Did exactly what I needed on a small bike.
Axiom Trekk Seat Collar
The solution for setting up a rear rack without band clamps, which can be especially useful for riders on carbon or aluminum bikes.
The amount of load you can apply to the rack with this setup depends more on the type of rack you are using, so there is no recommended weight limit for this seat collar, but I would suggest you don't run a carbon seatpost with this. The eyelets are drilled for M5 bolts, which are the same size you use with your bottle cages, and the full alloy construction is plenty durable.
Alloy construction. 2 x M5 rear threaded eyelets, made for a 31.8mm seat tube
Reviews
Average rating: 
based on 4 reviews.
seat collar
Rating:
Reviewed By: C Michael T Fisher on 4/7/11
Was using it within 15 minutes.
Axiom seat collar 31.8mm
Rating: 
Reviewed By: Dennis olmstead on 4/15/10
My 31.8mm seat tube didn't fit through the collar, just into the large end but not through the small end. So I ground off the small end "lip" with a Dremmel tool and then slid the collar up the seat tube til it was even with the rear rack. The rack braces fit perfectly without bending them and I still use my old seat tube collar as before. Summary: it doesn't work as I expected, but with some modification it works well.
Axiom seat collar doesn't fit seat post.
Rating: 
Reviewed By: A customer from Durham, NC on 4/13/10
It doesn't fit my seat post.