Suspension Rubbers – What They Mean for Riders

A bump stop is a progressive rate conical rubber spring intended to have a soft initial contact, then quickly surge in stiffness to avert hard contact. These should be an integral part of a bike if you want to prolong its life and maximise your performance. Read on to find out how.

Bump Stops – What Are They?

Otherwise known as jounce bumpers, these devices are installed onto a bike’s suspension system to support shock absorption and provide extra cushioning.

Installing bump rubber guides prevents the metal parts of the suspension from rubbing together – which we all know is dangerous. In addition to this, they also limit an axle's upward movement. In doing this, the bump stops prevent your tyres from rubbing or hitting against the fender. They also offer the ability to add longer shocks to bike owners’ vehicles.

Bump stops also support the vehicle's suspension system, keeping the shock absorber in excellent condition since they are designed to bottoms out prior to the shocks.

What Does Bottoming Out Do?

When the bike's suspension is fully compressed and reached maximum compression travel, this is known as bottoming out. It causes the base of the shock body to come into contact with the bump stop, but without that rubber (or a broken one), an abrupt clunking noise and damage to shock internals is the result. Even worse, at high speeds, this can lead to severe damage to the rest of the bike; exhaust pipes, steering and your sump.

Bottoming out can do some major damage to your bike, especially if you've used a lowering kit on the vehicle. A bump stop helps to soften the blow, protecting both your vehicle and the rider. It's the last line of defence for your suspension.

When Should I Replace These?

Do you know how to check if your bump stops have disintegrated or become damaged over time?

Some of the signals that bump stops need to be replaced include:

  • Uncomfortable rides: Without these, you'll feel every thump.
  • Suspension sag: If you regularly haul heavy loads, bump stops are absolutely crucial as they absorb the weight and keep your vehicle from completely bottoming out (see previous points).
  • No signs at all: If your suspension is good, and you only ride smooth roads, you may not notice issues for months. The problem comes when you get a big hit and suddenly it's too late. Your suspension parts are bent or shattered. Check for cracks or crumbling, and make sure it isn't rock hard.

Are Bump Stop Rubbers That Important?

The short answer is yes. This is because their primary purpose is to limit suspension travel by making contact before any other suspension component comes into contact with something that may have the potential to cause damage.

Where shocks are concerned, a bump stop will halt the suspension travel before the shock bottoms out, preventing any damage.

We have a range of spring seats and shock spring retainers available here at Teknik Motorsport. For further questions, get in touch with our team on (02) 4732 2626.