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:
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.
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.
Note: The OEM MK7 GTI, Jetta GLI, & Golf R, MK8 GTI, MK8 Golf R, and others all share the same bumpstop length and durometers. Some have an extra ring to make them feel more stiff.