Quick note on the rack. I had it on that brother in the pic, and the tubing didn't fit so i filled the bracket with layers of rubber inner tube until it packed out, and then use some clamps that were speced to a high amount of force to attach it to the down tube.
I mention it as the tubing diameter for the brackets isn't that important in my opinion, and I worked on the road with it carry heavy loads (multiple paper reams for example) with no issue.
Quick note on the rack. I had it on that brother in the pic, and the tubing didn't fit so i filled the bracket with layers of rubber inner tube until it packed out, and then use some clamps that were speced to a high amount of force to attach it to the down tube.
I mention it as the tubing diameter for the brackets isn't that important in my opinion, and I worked on the road with it carry heavy loads (multiple paper reams for example) with no issue.