I felt like my old pannier attachment system had some shortcomings that I wanted to address, so this is what I came up with. The sliding clamp on the old system, though effective, was kind of clunky, and I wanted something a little more streamlined and to be adjustable for the best fit. I also wanted to simplify installation of the attachment system, and to be able to switch the attachment system to a new set of panniers without having to do a lot of measuring of individual components. The solution I came up with was to place all the attachment components on a plate, which then attaches to the pannier; that way, the various parts become one unit, that can be easily unbolted from a pannier and attached to a new one. The attachment system would work with Pelican style cases, ammo cans, top loaders, or any pannier that has a flat side that’s a minimum of 15 1/2” wide and 12 inches high. The attachment system is designed to work with Happy Trail racks, which are what I’ve had on my last two bikes.
This picture shows the major material used in the construction of the attachment system. The aluminum and steel items came from Metals Depot (an online metal supplier), and the ABS plastic sheet was from TAP Plastics. My design changed a little as it progressed (it always does), so I ended up having to buy some additional HDPE sheet plastic from Grainger. The rotary latches came from Amazon.
This is the lower support for the pannier. It’s made from three layers of 1/4” thick ABS plastic, glued into a block. The center section has embedded machine nuts, that create attachment points for the aluminum flanges, and for attaching the support to the backing plate. The block is made to fit tightly between the upright portions of the HT rack, to minimize movement of the pannier on the rack. The aluminum flanges were made from the 3/16” thick aluminum bar stock shown in the first photo.
This is the upper support for the pannier. It’s made from a section of the 1.5” by 1.5” aluminum angle. It sits on the top bar of the pannier rack. The L-shaped piece is made from a piece of 1/4” thick aluminum stock I had laying around from other projects. The L-shaped piece is tapped and then attached to the angle with a screw, and it’s also soldered to the angle with Alumiweld. The L-shaped piece provides a backup connection in the unlikely event that the rotary latch failed; it also can be used to lock the pannier to the rack.
This bracket attaches to the pannier rack, and is the anchor point for the rotary latch. It bolts into the threaded brass inserts that come with the HT racks. The two slots on the one side of the bracket allow positioning adjustments to the bracket, to fine tune the fit. The three slots on top allow positioning adjustments of the rotary latch.
These are the rotary latches. The screws from the latch thread into the aluminum block via three tapped holes. The latch and the block sandwich the pannier rack attachment bracket; the block allows the rotary latch to be adjusted from the top, without the need for a wrench under the bracket.
These are the pinch blocks, made from 1/4” ABS. They’re slotted so they can be adjusted. They’re slid into position to clamp the bottom part of the pannier rack, then tightened. They prevent the pannier from being dislodged if it’s struck from below.
This is the steel backing plate, made from 18 gauge steel. All the components bolt to this plate, and the plate then bolts to the pannier. At first I just intended to paint it, but after I realized that it would constantly need to be repainted due to contact with the pannier racks, I bought some HDPE plastic and covered the steel with that. The HDPE is attached to the steel with machine screws, which screw into tapped holes in the steel plate.
This shows how the latching mechanism is set up.
This is the completed attachment plate.
This is the attachment plate, attached to the pannier.
This is the interior of the pannier, after the attachment plate was installed. As you can see, none of the attachment hardware intrudes into the case.
The pannier latched to the rack.
I was pretty happy with the way the project came out. The total pannier weight was 14.2 lbs; that’s only 1.78 pounds heavier than the pannier with the old attachment system. I could have reduced that even further if I’d used aluminum instead of steel for the backing plate, but I used steel for the reduced project cost. The only really specialized tool I needed was a tap and die set; the rest of it was made with regular hand tools (drill, scroll saw, Dremel tool, etc). The attachment to the pannier rack is very tight and secure, but also very easy to remove once the rotary latch is opened. If you’re interested in more details about how the system was constructed, there are a bunch of photos here: