It was getting warmer, and I was getting tired of packing my lunch, laptop and other junk on my back as I commuted to and from work. No one likes a sweaty back!
I looked at a some possible trunk bags to use, but they are all limited. The ones that would be big enough to hold my stuff were either too expensive or too small. Most require that straps or clips or something to be wrapped around the rack in some fashion. I saw some with a quick release feature, but these required a special rack and are beyond my budget.
So I designed a setup for the rack on my bike. I have the cheapest rack I could get. It's a classic steel thing with the spring wire mousetrap thing to hold stuff on.
My requirements? Cheap. quick release and fashionable. I know most folks are OK with a milk carton zip tied to the rack, but I gotta be cool!
It's not that complicated to make, but you should have some basic skills with woodworking. I made it in an afternoon.
What I used;
1/4 plywood, about 1 ft by 2 ft.
Some small scraps of other wood.
4 small (1/2" by 1') angle bracing. (Lowes or Home Depot)
Some screws and nuts. I used about 10 10-32 by 1" long screws and 6 wood screws.
A plastic snap clip,(scavenged from some dead luggage)
A bag. I found a nice tool bag from Harbor freight, costs about $8.
Woodworking tools. A jigsaw or scroll saw, a drill. A bench sander or sandpaper. Paint/varnish.
You'll have to size the base to fit your rack.
My rack and most racks I've seen have a bar in the front. First decide how wide you want your rack. 8 inches worked for me. Cut a rectangle to your width and about 3 inches longer than your rack. Draw a center line down the long length and make a 1 inch tab that fits into the front bar section of your rack. You should have some extra at the back.
Now cut the length so it just fits flush to the inside of the back end.
How you make the perpendicular rear part depends on your rack. My rack has a large reflector mount welded on the back that is perfect for my mount system. The idea is to have the front end of the base slip under the front bar and the back end held on by a single clip.
As seen in the photos, a smaller piece of wood sits perpendicular to the base and slots into the back part of the rack. This part extends below the top of the rack by and inch or so and thus prevents the base from shifting left and right and back. I made a single dovetail in the base and used some metal corner braces to make this part stronger.