DIY Roof Rack Cross Bars





Introduction: DIY Roof Rack Cross Bars

About: Awesome Gear I've designed myself.

My Buick SUV didn't come with any cross bars. I saw a set on Ebay for about $120.00 but still, I'd have to figure out how to mount it to the roof rack I bought. A trip to the hardware store and $10.00 later, I came up with this setup which worked great. 

This instructable took me 3 months to put together. Well, the actual project only took about an hour but I had to make sure it  held up to all our Summer travel. Now that it's tested here's what I did.  

Step 1: Cut the Bars to Length

The bars are cut from 3/4" electrical conduit. A 10' piece cost me about $2.00. I measured the distance between the roof tracks and added 6". I then cut 2 bars the same length.

The roof rack sits right on top of the cross bars. This particular rack has six bolts that protrude out. Accordingly, I drilled out 6, 1/4" holes in each bar. The holes at the ends are drilled all the way through so they can bolt together. To keep the holes in line i just measured and marked their positions along the seam of the conduit. 

Step 2: Mount the Bars to the Rack

To bolt it together I installed each bolt loosely and then tightened them up from the outside moving towards the middle. Once it's all together, 4 bolts are sitting in holes drilled along bar and two bolts are connecting it to the rack. 

To improve the look of the finished product I added end caps to the ends of the bars. 

Step 3: Prep Your Hardware

Here's what you need for hardware:
4, 1/4" bolts
16, 1" diameter 1/4" washers
4, 3/16" lock washers
4, 3/16" nuts
4, 3/4" conduit hangers.

To help with installation I cut grooves into each 1/4 bolt. You want them just long enough so they don't interfere with the conduit while they're sitting in the hangers. The bolts I bought were too long so I cut them down to 20mm long. That's the only modification you need to make. 

Step 4: Roof Mount Installation

Place 2 washers on a bolt. Slip the washers into the track keeping the bolt in them. I didn't have any trouble with them fitting right in. Place two washers on top of that. Now spin the hanger on the bolt. Use a flat head if you need any help here. To slide the front mounts in place I had to temporarily remove a bolt from within the track.  

Step 5: Tighten It All Down

Measure the mounts so they are placed square on your roof. Spin the hangers until they are tight and facing the right way. You'll have to use a flat head to help get this done. Next place the rack into the mounts and center it. First tighten the bolt against the conduit. To lock the bolt in place tighten the nut down against the mount. Make sure you have a lock washer in between. 



    • Water Contest

      Water Contest
    • Oil Contest

      Oil Contest
    • Creative Misuse Contest

      Creative Misuse Contest

    14 Discussions

    Great tutorial. This will be perfect for my Mazda 3. One question though:

    Where on Earth did you manage to find the 3/4" conduit hangers/beam clamps? I can't find that size anywhere.

    Thanks for the awesome idea.

    1 reply

    Your Mazda3 has built in attach points. Just remove the short plastic anchor point covers which slide/snap into the track covers that run the
    length of the roof.

    I'd like to make one correction on this tutorial. The pieces that you called conduit hangers are actually known as beam clamps. I set out to get the parts to do this myself and had a hard time finding conduit hangers that looked like that. lol. Otherwise, awesome write up!

    Beautiful pictures!

    Pvoss1, the cast metal clamps are actually called "Beam Clamps". Traditionally they are used to provide a threaded fastener attachment point on a (thick flat metal) structural component like an i-beam. The clamp is slipped onto the beam's flat edge, (where our author has placed the 3/4" EMT conduit), and is secured by tightening a fastener down that clamps/ secures it to the beam like a vice. The other threaded hole is then available to use for attaching your desired component, such as a conduit hanger, electrical junction box, all-thread, support chain...etc. Electricians, Plumbers, HVAC and other trades use these extensively to suspend and support conduit, pipes, ducting, etc. I just wanted to ensure that everyone understood the way these are typically used because they are very uhhh...useful, that way too. :) Very good Instructable, thank you!

    Key component, the cast metal clamps - what are they called? Which hardware store did they come from? Thanks!

    1 reply

    They are electrical conduit hangers. I bought these at home depot for about $1.25 each.

    Awesome! I had the same issue, +$100 bucks for a cross bar that cost them a few bucks. Great idea! Will be implementing this weekend!

    Sir, you are a genius. I have roof racks on my matrix but when using them for my cargo box I have no room for my auxiliary lights. I think I'm going to have to steal your idea and improve a little. Finding a way to flatten the pipe a little to give it a more oval shape is an example, that way you can fit other roof rack accessories since most of them deal with squared and oval bars. Also adding a lock nut to the mount on your car to ensure vibrations wont loosen them over time or loctite (unlikely but safety first right?)

    For extra mounting safety, you could drill holes in the pipe so that the bolts used to fix the pipes to the clamps go into the pipes securing them just that bit extra. Cool idea! I might be able to adopt this method for my car. I build my own custom roof mountings too.

    What Audrey said, plus, I like the opening image, the colour/monochrome is cool.