What a 22mm bump stop does
A bump stop is a rubber or polyurethane component that sits at the end of your suspension travel and stops your suspension from compressing all the way to the frame. The Energy Suspension 22mm bump stop is a specific diameter and durometer (hardness rating) designed to fit certain suspension setups — most commonly on lowered vehicles or performance builds where the suspension geometry has been altered from factory specs.
When your suspension compresses fully without a bump stop, metal-to-metal contact occurs between the suspension arm and the frame or chassis. This creates a harsh, sudden stop that can damage both components and transfer a violent jolt through the entire vehicle. A bump stop absorbs that final compression gradually, protecting your suspension and frame while also improving ride quality during extreme compression events.
The 22mm measurement refers to the outer diameter of the bump stop itself. Energy Suspension makes bump stops in several diameters because different vehicles and suspension designs require different sizes to fit properly in the available space and to provide the right amount of travel before bottoming out.
Key Takeaways
- A 22mm bump stop prevents metal-to-metal contact when your suspension compresses fully, protecting the frame and suspension components from damage.
- Energy Suspension bump stops are made from polyurethane, which is more durable than rubber and resists oil and heat better over time.
- You need a 22mm specifically if your vehicle's suspension geometry or lowering setup requires that diameter to fit in the available space.
- Bump stops wear out gradually and should be inspected if you notice a harsh bottom-out feeling or clunking sounds during hard compression.
When your vehicle needs a bump stop replacement
Bump stops compress and harden over time, especially on lowered vehicles or cars used for track driving where suspension compression is frequent and severe. After several years, a worn bump stop no longer absorbs compression smoothly — instead, the suspension bottoms out with a harsh clunk or bang that you feel through the steering wheel and seat.
If you recently lowered your vehicle and the suspension feels like it's hitting a hard stop during normal driving, or if you hear a metallic clunk when going over bumps, the bump stop may be worn, missing, or the wrong size for your new ride height. Lowering kits sometimes come with new bump stops sized for the reduced suspension travel, but not always — checking this during installation prevents problems later.
Track-driven vehicles and performance cars that see repeated hard cornering and braking wear bump stops faster because those maneuvers compress the suspension repeatedly. If you drive on a track or autocross course regularly, inspect your bump stops every season or every 5,000 to 10,000 miles of track use.
How to measure and confirm you need 22mm
The easiest way to confirm your vehicle needs a 22mm bump stop is to check your vehicle's service manual or suspension documentation. If you're building a custom suspension or replacing a worn component, measure the diameter of the existing bump stop with calipers if one is still present, or measure the bore (hole) where the bump stop sits on the suspension arm.
If you're ordering a replacement for a lowered vehicle and don't have the original documentation, contact the lowering kit manufacturer or the shop that performed the work. They can tell you the correct diameter and also whether the bump stop is a direct replacement or if suspension geometry changes require a different size.
Energy Suspension bump stops come in several diameters: 16mm, 18mm, 20mm, 22mm, and larger sizes. Ordering the wrong size means the bump stop either won't fit in the bore or will be loose and ineffective. When in doubt, measure twice before ordering.
Installation and what to expect
Replacing a bump stop is straightforward on most vehicles. The bump stop slides or presses onto the suspension arm or into a bore on the frame, depending on your suspension design. You'll need to lift the vehicle safely with a jack and jack stands, then locate the worn bump stop and remove it by hand or with light prying if it's stuck from age.
Clean the bore or mounting surface with a wire brush to remove any dirt, rust, or debris. Slide the new 22mm bump stop onto the suspension arm or into the bore. It should fit snugly but not require a hammer — if you're forcing it, you may have the wrong size or the bore may be damaged. Once installed, lower the vehicle and test the suspension through its full range of motion by bouncing on each corner to confirm the bump stop compresses smoothly.
Energy Suspension polyurethane bump stops are stiffer than OEM rubber versions, which means they provide firmer support but may feel slightly harsher on very rough roads. This is normal and intentional — the trade-off is longer lifespan and better performance during hard driving. If the ride feels too firm after installation, you can return to a softer rubber bump stop, but polyurethane is the standard choice for lowered and performance vehicles.
Compatibility with lowering kits and coilovers
Lowering kits and coilover systems reduce suspension travel compared to factory setups. When you lower a vehicle, the bump stop must be positioned to stop compression at the new, shorter travel limit. Some lowering kits include new bump stops sized for the reduced travel; others do not and rely on the existing bump stop to work at a different compression point.
If you install a lowering kit without new bump stops, the suspension may bottom out before the original bump stop engages, or the bump stop may engage too early and limit suspension travel. A 22mm bump stop from Energy Suspension is often the correct replacement for popular lowering kits on compact and midsize vehicles, but always verify against the kit documentation or contact the kit manufacturer.
Coilover systems often come with adjustable bump stops or require specific sizes to match the coilover body diameter. If you're upgrading to coilovers, the manufacturer will specify the correct bump stop size — do not assume your existing 22mm bump stop will work with a new coilover setup.
Polyurethane vs. rubber bump stops
Energy Suspension manufactures bump stops from polyurethane, a synthetic rubber that is harder and more durable than natural rubber. Polyurethane resists oil, heat, and UV exposure better, which means it maintains its compression characteristics longer and doesn't degrade as quickly in engine bays or near hot suspension components.
Rubber bump stops, typically found on factory vehicles, compress more easily and feel softer initially, but they harden and crack over time — especially in hot climates or on vehicles that see frequent hard driving. Once rubber hardens, it no longer absorbs compression smoothly and bottoming out becomes harsh and sudden.
The trade-off is that polyurethane bump stops feel firmer from day one. On a lowered performance vehicle, this is desirable because it provides consistent support and prevents bottoming out during aggressive driving. On a stock vehicle driven gently, the slightly firmer feel may be noticeable but is not a problem — it straightforward means the suspension will never bottom out unexpectedly.
Frequently Asked Questions
How do I know if my bump stop is worn out?
A worn bump stop produces a harsh clunking sound when the suspension compresses fully, usually heard over bumps or during hard braking. You may also feel a sudden jolt through the steering wheel or seat instead of a smooth, gradual stop. If the bump stop is cracked, flattened, or missing pieces, it needs replacement when ready.
Can I use a different diameter bump stop if 22mm doesn't fit?
No. Using the wrong diameter means the bump stop either won't stay in place or won't engage properly when the suspension compresses. Always measure the bore or mounting surface and order the correct size. If 22mm doesn't fit, measure again or contact the suspension kit manufacturer to confirm the correct size.
Do I need to replace both sides of the suspension?
If one bump stop is worn, the other is likely worn too since both sides experience the same driving conditions. Replacing both at the same time ensures consistent suspension behavior on both sides and prevents one side from bottoming out before the other.
Will a stiffer bump stop make my ride harsher?
Only during extreme compression — when the suspension is being pushed to its limit. During normal driving on smooth roads, you won't feel the difference. On very rough roads, a polyurethane bump stop may feel slightly firmer than a soft rubber one, but this is the intended trade-off for durability and performance.
How long does a bump stop last?
A polyurethane bump stop from Energy Suspension typically lasts 5 to 10 years on a street-driven vehicle, longer if the vehicle is driven gently. Track-driven vehicles may need replacement every 1 to 3 years depending on use intensity. Lowered vehicles wear bump stops faster because suspension travel is reduced and compression is more frequent.