Anyone who has spent enough time off-roading in an older vehicle has experienced the jarring sensation of bottoming out their suspension. You’re cruising down an unmaintained service road, an unexpected whoop catches you off guard, and your vehicle lurches forward with a jarring shudder. Not only is this experience uncomfortable, but all of the force from the vehicle’s momentum has to go somewhere when your suspension can no longer absorb it, which can damage the suspension, frame, and alignment.
Luckily, automotive manufacturers have introduced a second line of defense: bump stops. What once were simple pieces of rubber have evolved into intricate systems with engineering comparable to racing suspension. Today, they not only protect your suspension from the impact of bottoming out but also soften impact forces and improve control for precise off-road maneuvers. In this article, we’ll look at how this product has evolved through automotive history, culminating with Perry Parts’ release of a 3D-printed version.
Table Of Contents
Early Bump Stops
Pictured: Factory rubber bump stop on a refurbished 1979 Toyota Pickup. Image from Bring A Trailer.
Bump stops were first introduced to the off-road vehicle market in the early 1970s. Their intent was simple: to prevent metal-on-metal contact between the suspension system and the chassis. These rudimentary pieces of rubber were mounted to the axle or frame and could absorb the force from harsh impacts before the suspension reached maximum compression.
Despite their simplicity, early ones were a massive improvement over metal-on-metal impacts, prolonging the suspension system’s lifespan and dampening major impacts.
Polyurethane & Rubber
The factory bump stops in most off-road vehicles, including the 5th Gen 4Runner, are now made with polyurethane foam and rubber.
Within the decade, automotive manufacturers began to seek a more durable and dynamic material for their bump stops. Polyurethane and rubber was selected for its shock absorption. At the same time, early prototypes were developed for progressive response, which allowed for varying levels of compression based on the speed and force of the impact.
While bottoming out your suspension was still a jarring experience with rubber alone, this progressive polyurethane advancement began to take the edge off. In fact, many automotive manufacturers continue to use polyurethane in their entry-level 4WD vehicles to date. This application typically utilizes a microcellular foam and/or rubber.
Hydraulic & Air
Pictured: A long-travel rear suspension setup with a hydraulic bump stop. Image from Rebel Off-Road.
It wasn’t until the late 1990s and early 2000s that the aftermarket started to take notice of bump-stop innovation. Off-road races like the Baja 1000 had reached the peak of their popularity and the demand for high-performance off-road vehicle components was never higher.
Hydraulic and air bump stops were introduced to the market, the former using compressed nitrogen to absorb impacts and the latter using valved hydraulic fluid. Both functioned similarly to high-performance racing shocks, allowing for terrain-specific customization and massively improved ride quality through harsh conditions. Some of the biggest names in off-road suspension including Fox and King sell improved variants of these today.
Rise Of 3D Printing
From the early 2000s up until just a few years ago, bump stops remained effectively the same in their construction and function. Outside the automotive world, however, a new technology was gaining traction that would later transform manufacturing in dozens of markets: 3D printing. What started with brittle plastic trinkets has progressed into an ultra-precise automated assembly line for any purpose. They even have metal printers now.
Recent developments in extruded materials, computer-aided design (CAD) software, and printing techniques have not only surpassed the design capabilities of any mold but have put those capabilities in the hands of entrepreneurial small business owners. One such entrepreneur is Patrick Perry, a former Apple engineer who saw an opportunity to introduce the overland world to the capabilities of 3D printing.
Find It Online
- 4Runner Bump Stops: Check Price
Perry Parts: How It’s Made
Check out this fascinating video where Perry explains the rationale and testing behind his product!
This brings us to the most recent evolution in the history of bump stops. In just the past couple of years, Perry has developed sets made using a 3D printer. The magic of manufacturing with this process is that it allows for unlimited design and customization down to fractions of a millimeter. Through trial and error, Perry used this unparalleled precision to create a product with the following features:
- Variable stiffness, designed for both a soft initial activation and improved bottom-out protection
- Compression damping ports: become blocked by high-speed forces; internal pressure increases resistance
- Fused pellet fabrication using hydrolytically-stabilized thermoplastic polyurethane (TPU): superior durability to standard 3D filament
If you’re interested in learning more about what each of these terms means, check out our post – Perry Parts, from concept to production.
So What Does This Mean?
Those are a bunch of technical terms, but what does this actually mean for you as a consumer? Having run these on my own vehicle for several thousand miles, I can say with confidence that the juice is worth the squeeze (pun intended). Through advanced design processes and rigorous testing, Perry and his team have created a bump stop that rivals, if not exceeds, the performance of air- or hydraulic-based systems at a fraction of the cost. In fact, the progressive damping has been so effective that since installing Perry Parts on my rig, I haven’t felt the jarring sensation of bottoming out my suspension even though I’ve undoubtedly maximized my compression several times.
If you’ve taken the time to improve your vehicle’s suspension, there is no reason why you shouldn’t protect that investment with a set of these. They’re astoundingly affordable and can be installed in less than an hour. Whether your mission is rock crawling, overlanding, or simply defending your daily driver from those pesky surprise potholes, the Perry Parts lineup will eliminate those jarring shudders and improve the longevity of your suspension and chassis. Moreover, Perry and his team have proven that tactful innovation and honest business have the potential to transform an entire market for the better.
Final Thoughts
When I first got my hands on Perry Parts’ bump stops, I couldn’t believe they had come from a 3D printer. At first, I was worried they wouldn’t hold up to the harsh Colorado climate, but time has proven the exact opposite. The more that I learn about the innovation and intricate design poured into these, the prouder I am to be running them on my 4Runner.
What do you think? Would you trust a 3D-printed part to protect your vehicle’s suspension? What are you currently running on your rig? Let us know in the comments below!
