How to Make Your Own Roof Crossbars

DIY Roof Rails (for any vehicle with side rails).
Roof rails are necessary for any car-top accessory, like cargo baskets, ski racks, or bike racks. And they can be pricey: a pair of rails from the main manufacturers regularly costs somewhere around $100, and often require additional parts like vehicle-specific brackets just to attach them. You’ll need:
Steps
1. Figure out where to mount the bars. On a 2004 Jeep Liberty, there are 4 factory-drilled holes on the top of the crossbars. If you line up the bars with those holes, which guaranteed they’d be parallel to each other.
2. Drill holes for eye bolts. If you’re interested in adding eye bolts to help tie down loads, this is a good point to drill holes for them.
Find out what diameter your eye bolts are.
Choose a drill bit that is exactly the same size.
Note: even if you don’t want to have the eye bolts on your bars all the time, you might as well drill the holes now so that you don’t have to later. Since you’re just using ordinary hardware, you can add or remove the eye bolts anytime you want.
3. Drill holes for U-bolts.
Lay the crossbars on your side rails and grab one of your U-bolts.
Using your U-bolt, mark where holes need to be drilled on the underside of your crossbar.
Repeat for the other side, and the second bar.
Drill where you marked.
Note: you’ll notice in the early pictures that four holes are drilled per side, and none are drilled for the U-bolts. The original plan was to secure the crossbars using regular hex bolts inserted through the crossbar and into the side rail. U-bolts were used instead, so those holes became superfluous.
4. Grind. Notice that the side rails on the Jeep are curved. That is the case for most vehicles.
If you use square tubing and just rest the tubes on the curved side rails, nothing will sit flat across your cross bars, and they will look bad.
One solution is to use circular steel tubing. The other solution is to grind out some metal from each place where the tubing rests on the side rails. You’ll need a metal grinder for this step.
Take off a tiny bit at a time until you see that the bars are beginning to line up parallel.
5. Paint. When you see that the bars will sit the way you want them to, choose a color of spray paint, hang your rails and hardware, and paint them. This is strictly unnecessary, but the extra effort and $5 will make your DIY crossbars look great.
6. Mount. Once everything is dry, place your crossbars on the side rails, slide the U-bolts through underneath, and tighten the nuts until it becomes somewhat difficult to turn the wrench by hand. If you want to prevent scratching to the side bars, add a small piece of gasket between the side bars and the cross bars before tightening the U-bolts. You want the U-bolts to be firm, but they don’t need to be so tight that they crush your side rails. You should be able to grab a hold of the rails and rock the vehicle without the bars moving.
7. Buy yourself a nice dinner. You just saved somewhere between $50-$200 dollars!