APR Lowering Bumpstops are here! They improve handling and ride quality and are designed for use on lowered vehicles such as those with APR Roll-Control Lowering Springs.
Bumpstops are a critical handling and ride-quality component of your suspension system, but they are often completely overlooked. Most setups are either running the factory bumpstop, which are too tall causing constant engagement during normal driving, cut bumpstops, which remove the progressive dampening, or they've removed them all together! All of these scenarios hurt handling and make the ride harsh.
APR Bumpstops were designed using a balance of durometer (hardness) and length to tune comfort and handling under normal and aggressive driving scenarios. The balance takes the following into account:
Length:
A longer bumpstop, like the factory units, will have more volume to absorb a harsh impact. But during normal driving on a lowered vehicle, they will constantly contact, which impacts both handling and comfort. The quick engagement can disrupt handling and cause driver discomfort. We've shortened the bumpstop to ensure that they work on a lowered vehicle, but keep them tall enough so they have enough volume to absorb a hard hit.
Durometer (hardness):
An overly soft bumpstop is comfortable, but can't absorb enough energy to protect from damage. Likewise, an overly stiff bumpstop will impact ride quality, and impact handling negatively. Testing various setups we strike a balance by increasing stiffness to provide better handling without going overly stiff as to impact comfort. The bumpstops also have a progressive rate to them with a soft "nose." This allows the bumpstop to gently engage as to not disrupt handling. It's also less noticeable to the driver, aiding in the comfort of the driving experience.
Specifications:
Material: PUR
Front / Rear Durometer: 75A (~50A OEM) / 65A (~55A OEM)
Front / Rear I.D.: 19mm / 17mm
Front / Rear O.D.: 56mm / 59mm
Front / Rear Length: 40mm (56mm OEM) / 80mm (110mm OEM)
Note: The factory models are the same bumpstop length and durometers. Some have an extra ring to make them feel more stiff.
Features:
- Designed to improve both handling and comfort on vehicles lowered with APR lowering springs
- Height custom designed, not too low, not too tall
- Durometer is stiffer than stock to prevent bottoming, but not so stiff as to ruin ride quality
- Progressive rate with soft nose to provide gentle engagement so the spring rate doesn't go too high, too fast
- Black polyurethane material for durability and longevity
- Installs in place of factory bumpstops
- Includes all 4 bumpstops, two front and two rear