I would like to add a rear rack to carry photo equipment and was looking at the Bontrager MIK Utility Trunk Bag with Panniers that would slide onto a BackRack Disc MIK (Topeak has a similar product, so the brand is secondary). Problem is, my FX Sport Carbon 4 does not have mounting holes for the rack. Obviously I don't intend to drill anything into the frame, but I was wondering if it is still possible to attach a rear rack. I have access to a TIG welder and CNC and can machine simple aluminum (6061) brackets and attach them to the frame using rubberized J clamps. Sorry the system won't let me post urls.

So I am able to modify the rack while retaining its slide connector/attachment to the bag. Will the carbon frame tolerate the weight? Any other ideas, tips, or concerns? Grateful thanks to all.

There are a couple of rear pannier racks on Amazon that mount to the Bike seat post and mount to the seat stays using support brackets.

West Bikimg has one that mounts on the seat posts and seat stays.

My bike has the IsoSpeed decoupler suspension at the seat post and seat stays, so I am not sure I can attach to the seat post and another attachment point. I was thinking about attaching to the wheel stays at the back and seat stays near the seat post, using friction mounts.

There are some other models that are seat post only. Your max carrying weight declines with seat post only models. The seat post support smaller packs. You can’t do the larger packs that partially go over the wheel base.

You might have to tolerate a small amount of rattling noise with a seat post only model.

Trek built the Sport models as pure high end fitness bikes. They didn’t really design the Sport to easily accommodate commuter accessories.

Perfect summary of the problem. Ultimately, I prefer spending my free time riding the bike instead of machining fitments for it.

This was my solution to adding a rack to a Sirrus Pro Carbon. I used a Giant seat clamp which created an attachment point on the clamp and the Sirrus has pre drilled holes with metal inserts in the frame.