Build a Cargo Rack for Your Bike From a Crutch and a Wood Plank

by ArtisanEclectic in Outside > Bikes

583 Views, 3 Favorites, 0 Comments

Build a Cargo Rack for Your Bike From a Crutch and a Wood Plank

IMG_20141102_124932_222.jpg

I made this back in 2014 and I still use it today. I bought this bike off Craiglist and even though it had a squeeze bulb horn, basket, and bell, it didn't have a cargo rack. After looking online I found that they were not only pretty expensive, they looked like something I could make myself. Around that time, I found a set of crutches sticking out of a trash bin. Strong and light tubing, just what I needed. I remembered the rack I had on my last bike. It was a Blackburn rack with a simple design, just a horizontal surface, no moving parts and lots of places to hook bungee cords to. Add to that a scrap of 1 x 10 pine, a handful of stainless steel hardware, a drill and a hacksaw, and I was ready to go!

Supplies

Be sure to wear safety glasses when you are cutting and drilling metal. If you don't have experience using tools, you should ask someone that does to help you.

All you need is a pair of aluminum crutches that no one else is using. (That part is important) If you don't already have a set in your garage, you could probably ask around until you find someone who does.

A sturdy plank. Decorative knot is optional.

A handful of stainless steel hardware. See text.

Some kind of finish for the wood. Varnish, oil or wax. Even paint, if you don't have a soul. =)

As for tools, You'll need a drill, a hacksaw to cut the tubing and a round file and some sandpaper to debur and clean up the ends of the tubing after it's cut. If you don't have a file, a dowel wrapped with sandpaper will work just fine. Aluminum is a fairly soft metal.

A table saw would be nice for ripping the wood but a circular saw or a hand saw will work just fine as well.

Assess the Situation

IMG_20140729_171448_145.jpg
20160214_101904 (2).jpg

If you have ever seen more than one bike, you've probably noticed that there are a lot of different designs, but they are basically the same. Note: This probably won't work on racing bikes or bikes with a rear shock absorber. But you likely won't be putting a rack on those types of bikes anyway.

Your frame is usually composed of several triangles. Your rack will be no different. You will need at least two attachment points on the bike. The third point on your triangle will be where the tubes of the rack meet. The bike itself will be the third side of the triangle. We'll be working on the aft triangle of the frame. But the same principles could be used on the forward end as well, using the fork as the mounting point.

Go to the furthest part of the aft triangle on your bike. Just above the axle, there should be something called a lug. Kind of a protrusion from the frame with a threaded hole in it. That's your first attachment point. Now look at the frame right below the seat, where the aft triangle joins the seat tube. Two tubes will go down to the axle. On my bike there is a web that connects those tubes between the tire and the seat tube. There may already be a hole in that web or you may need to drill one. I DON'T ADVISE DRILLING HOLES IN ANY OF THE TUBES THAT ARE PART OF THE FRAME! YOU COULD WEAKEN THE FRAME TO THE POINT OF FAILURE.

Creating the Platform

IMG_20140729_171430_218.jpg
IMG_20140729_163549_591.jpg
IMG_20140729_163533_841.jpg
IMG_20140729_155637_485.jpg
IMG_20140729_170348_386.jpg
IMG_20140729_171440_880.jpg

OK now the fun part. We get to start cutting stuff up! Let me start by saying that this is how I did it. I won't be including measurements because I really didn't measure anything. I just held it in place and marked where it should be cut or drilled.

So, to start with, I cut the edges off of my 1x10 plank. Then I took each of the pieces and rotated them down 180 degrees so the two cut edges are facing out. Glue these pieces together in this position. This makes the edges thicker and supports the pipe that we will screw in place later.

Next we move to the fwd attachment point that we located in the first step. We are going to need a total of 6 pieces from the crutch. Two pieces for the horizontal supports. These will include the S curve plus about 3-4 inches to attach it to the forward attachment point. Two pieces to attach to the bottom lugs and hold up the horizontal Platform. We also need one short piece to attach to the fwd point and support the platform. And a slightly longer piece that attaches under the platform and supports the diagonal support tubes.

Now disassemble the crutch, cut the pieces as needed and take the smallest piece and attach it under the seat with a stainless steel bolt and locking nut. Be sure to leave enough length to attach the curved piece with stainless steel bolts and locking nuts. Then use screws to attach the curved tubes to the wood platform leaving enough space to fit the ends outside the frame of your bike and attach to the ends of the first tube. Next, figure out where the diagonal tube will land under the platform to hold it level, then drill and screw the other short piece in place. Attach the lower ends to the lugs and the upper ends to the short piece. It's probably easier to look at the pictures and your bike than it is to explain.

Finishing Up

IMG_20140801_194311_278.jpg
IMG_20140729_171417_842.jpg
20160214_101904.jpg

Be sure to clean up the cut ends of the tubing so it does not snag or cut someone. Double check that everything is tight and check again after a couple days or if you hear any rattles. I used Nylon locking nuts and they have not come loose after about 7 years of hard riding and some pretty heavy loads.

Put some finish on the wood to keep it shiny and find the best places to attach a bungee cord. You can use the open ends of the tubing or even add some screw eyes to the bottom of the wood if you need to. Just be sure they are large and strong enough to hold the load you plan to carry.

Then just load it up, tie it down and head out!

Thanks for checking out my little tutorial and if you have any questions, just leave them in the comments.

Ciao!