Building A Rollcage - Cage MatchPosted in How To: Body Chassis on February 17, 2014 0) (
When we add most modifications to our rigs, we can’t wait to go out and test them. A rollcage is the exception. It is a component that we hope we never need—but when you need one, you want to be very confident in its abilities. And just as apples can vary from Red Delicious to Granny Smith, not all rollcages are created equal. Materials, welding techniques, design, and mounting all play a part in the overall safety of the cage.
Cage materials typically include hot rolled electrically welded (HREW) steel, drawn over mandrel (DOM) steel, and chromoly DOM steel. In respective order, they increase in strength but also increase in price. In our opinion, DOM offers the best bang for the buck, with chromoly typically reserved for racing applications where the additional strength allows for lighter, thinner material to be used. If you have to use pipe on your rig, save it for your rock sliders.
When designing a cage you must strike a balance between strength and packaging. Even the best cage is worthless if you can’t get into your rig to drive it. Triangulation is an important feature to add strength, as the shape is inherently stronger than a square at absorbing loads from various directions. Try to break up large, unsupported areas (like the roof area above the occupants) with gussets and diagonal bars wherever possible to ensure that the cage does not flex or fold under a hard impact to a corner.
Steel can be stick welded, MIG welded, or TIG welded. MIG welding is the most common and a great balance between strength, aesthetics, and time. TIG welding will give your cage that race car look but adds considerable time and expense to the welding process, and using the proper filler rod is critical.
Another factor that is important regardless of the welding technique but critical for TIG welding is tight-fitting joints where the tubes come together. This is analogous to doing proper prep work for a paint job -- it is time consuming but is often the most important step.
Even the best cage isn’t worth a lick if it parts ways with your vehicle in a rollover. The best option is to mount the cage to the frame, either by welding it directly or using plates and bushings to isolate vibration. Mounting the cage to the frame also strengthens your chassis and makes it more rigid. If you can’t mount the cage to the frame, the next best option is to position the feet of the cage over the cab mounts. Use large foot plates (such as 6 inches square) with varying sizes on the top and bottom to resist just punching through the sheetmetal.
Bolt-In, Weld-In, or Custom. Which Is Best for You?
Many cage options are on the market, particularly if you have a popular vehicle like a Jeep Wrangler. The costs can vary widely both in terms of purchase price and installation. So how do you know which is best for you?
Bolt-In: Rock Hard 4x4 offers cages that clamp together inside of your Wrangler or Cherokee. They are inexpensive to ship and easy to assemble in your driveway, saving money. As a bonus they add rigidity to your unibody vehicle.
Weld-In: The next step up in strength is a weld-in cage, such as those from 4x Innovations for Toyotas and the Lazer Fit cages from Poison Spyder Customs for Wranglers. These show up on your doorstep prebent and notched for easy installation, and both companies offer some options for customization. Even if you hire a fabrication shop to install the cage, you will still save money with a kit when compared to custom fabrication.
Custom: If you have a vehicle with little aftermarket support, like a Nissan Pathfinder, custom fabrication is likely your only option. But even if you have a more common vehicle, a custom cage can be built to your specific needs. This will stand out from the crowd, but at an added price and downtime for installation when compared to a cage kit.