Wednesday, October 10, 2012

No More Roll Pins in Tire Carrier Hinge Kit Designs

Competition 4x4 will no longer be using roll pins as part of their tire carrier designs. Starting October 10th, 2012, kits will not ship with a roll pin.

The purpose of the roll pin is to provide an automatic height setup for first time fabricators and repeat builds. However, many people became confused in thinking that the roll pin’s sole purpose was to hold the actual spindle shaft in place. 

We still recommend using a sleeve with all our tire carrier hinge kits and fully welding the sleeve into the bumper instead of the shaft, therefore reducing the amount of heat and potential crystallization and weakening of the spindle shaft. We do recommend putting a few light tack welds on the bottom of the spindle shaft to the inside of the DOM tubing sleeve. 

The DOM tubing sleeve should be welded into the bumper while the spindle shaft is inside of it at the correct height. As the sleeve heats up from the weld, it will shrink the internal diameter and pressure fit itself onto the spindle shaft. The pressure fitment and tack welds on the bottom are more than enough to hold the shaft into place. 

Removing this item from future kits will create less confusion and help to keep pricing low from a slight reduction in labor.

Tuesday, October 9, 2012

The Most Important Components to Consider When Building a Tire Carrier – PART 3


The third most critical part of your 4x4 bumper and tire carrier is how it directly mounts to the vehicle. Obviously every vehicle mounts in a different patter and location; however, the bumper should always be mounted or reinforced directly to the frame or chassis of the vehicle. This provides a solid foundation to reduce flex and movement within the tire carrier and bumper system.  

This poses a problem for many vehicles like the Jeep Wrangler that use a very thin cross member (1/16” - 1/8” thick) to  bolt the rear bumper to. This can be solved by using an ‘L’ shaped frame tie in bracket that secures the back of the bumper to the outside of the chassis vehicle frame. This ensures the bumper is mounted directly to the frame and eliminates significant movement within the overall tire carrier design. If a frame tie in bracket cannot be found for your vehicle, consider fabricating a set up from ¼” thick steel with a welded in gusset for added strength. 
Mounting directly to the body of the vehicle should be avoided at all costs due to the very thin body metal.  Even if you’re using backing plates with the body to increase the surface area, it’s still pulling on very thin material and will eventual tear, oblong, and or fail. If you must have upper mounts for your swing away tire carrier that mount to the body, try mounting through the body and reinforcing into roll cage tubing in that corner of the vehicle if available. 

Immediately you’ll notice a dramatic improvement within your tire carrier system after being reinforced directly into the frame/chassis of the vehicle. Now you should be able to hold onto the tire of your tire carrier and try to aggressively shake it back and forth with little to no movement within the entire system. The elimination of this movement and flex has now increased the strength of the entire system, especially the hinge and latch mechanism as it reduces fatigue stress. 


Installing or creating a pair of rear bumper frame tie in brackets is an easy and inexpensive way to dramatically improve the strength and durability of your entire 4x4 bumper and tire carrier system. Reducing flex and movement within the system ensures durability and longevity as it reduces fatigue stress that would otherwise be loaded on the tire carrier hinge and tire carrier latch system.

Tuesday, October 2, 2012

The Most Important Components to Consider When Building a Tire Carrier – PART 2


This is the second most critical part of your tire carrier as it can dramatically reduce flex and movement within your tire carrier system. This is also the most overlooked part of the build. The latch needs to be able to support the weight of the tire carrier and shouldn’t just be thought of as a convenient spring lock mechanism. Remember, its movement and flex that causes fatigue on the pivot point that results in a tire carrier failure or breakage. 
A well-built tire carrier latch kit should reduce any lateral movement as well as forward to back. You should be able to try and shake the tire carrier forcefully by hand without any movement occurring. Consider using a latch kit that not only clamps the tire carrier swing arm down towards the bottom of the bumper but also clamps it back towards the front of the vehicle as well. 

The most durable tire carrier latch kit designs use a ‘C’ shaped metal backstop for the tire carrier main arm to fit snugly into. This ensures that no up or down movement can take place within the lower swing arm of the tire carrier. Lastly, this design type will use a threaded post/shaft/t-handle design to go directly through the top of the ‘C’ shaped bracket, through the swing arm, and into the bumper. 
Lastly, you should use a polyurethane pad for the tire carrier main arm to rest on while the carrier is in the fully closed position. No weight should be on the latch while closed, it should all be resting on the urethane pad. This will also reduce bending and stress fatigue on the main pivot point hinge.


Much like the swing away pivot point of your 4x4 bumper build, you shouldn’t go ‘cheap’ on your tire carrier latch kit. A well-built latch mechanism will complement the tire carrier hinge and provide a long lasting and durable combination. With the reduction of flex, stress, and movement from each of these items you can rest assured that your 4x4 bumper and tire carrier will be able to take any abuse you throw at it.

Wednesday, September 26, 2012

The Most Important Components to Consider When Building a Tire Carrier – PART 1

The Most Important Components to Consider When Building a Tire Carrier – PART 1

Whether you’re building a tire carrier for yourself or in a production run for others as a company, there are a few points to consider that will make or break your build:

  1. The swing away tire carrier hinge – this is the most critical part of your tire carrier and will make or literally break your design and tire carrier performance. You cannot go cheap on your hinge kit design as the entire system depends on the performance of this part. In order to determine what tire carrier hinge kit you need to purchase, consider the following items:

a.      How much weight will you be putting on your tire carrier?  

  • When using a 33” tire or smaller you may use a vertical type hinge kit with a 1-1/4” base diameter shaft. Many companies rate the shaft/kit at a 1000 pound load rating; however, this is incorrect. The 1000 lb. load rating only applies to a trailer application and is very different for a tire carrier. 

  • When using larger than a 33” tire, you need to use a kit with a 1-3/4” base diameter shaft or spindle. Again, many companies will rate the 1-3/4” diameter shaft at a load rating of 1750 pounds; however, this again is incorrect. 
  • For those of you building a tire carrier that will have Gerry can racks, over the tire racks, or more, you should be using a dual shear tire carrier hinge kit. A double shear tire carrier hinge kit will hold the top of the shaft to isolate all movement and therefore eliminate fatigue from bend stress. The dual shear tire carrier hinge kits are by far the strongest designs available and come in a wide variety for various tire carrier designs.

b.      Will you need an upright vertical design or face mount?

  • Many popular designs use a standard upright vertical type hinge; however, not all bumpers and designs can accommodate these types of kits. Be aware that face mount style tire carrier hinges are available that can mount directly onto the front of the bumper as opposed to on top. Not only are these very strong dual shear designs but they can save a ton of time and space for your build. 


Not only is excessive weight the determining factor in a failed tire carrier hinge; however, it’s also due to bend stress that can be eliminated from a dual shear tire carrier hinge kit, solid latch kit, direct bumper to chassis mounting, and pre-loading. We’ll discuss the tire carrier latch kit component in part 2 of this 4 part blog post.