Intro to compression
When it comes to motorcycle suspension, your rear shock plays one of the biggest roles in how your bike feels on the road or track. One of the most important – and often misunderstood – aspects of your shock is compression damping. Getting this right can mean the difference between a plush, confidence-inspiring ride and one that feels harsh, unpredictable, or wallowy.
When you ride over bumps, potholes, or even land a jump, the shock absorber compresses as the wheel moves upward. Compression damping is the system that controls the speed and resistance of this upward movement. Without compression damping, your suspension would blow through its travel too quickly, bottoming out and leaving you with a harsh ride and poor control. With too much compression, on the other hand, your suspension will feel stiff, transmit impacts directly into the chassis, and reduce traction. Think of compression damping like a gate that controls how quickly oil flows through the shock’s internal valves as it compresses. A smaller opening means less oil can move at once, making the shock stiffer. A larger opening allows freer movement, making it softer.
Most modern shocks have an external compression adjuster – sometimes even separate ones for low-speed and high-speed compression. Low-speed compression controls shock movement from slower inputs like cornering forces, acceleration squat, and weight transfer. Adjusting this helps with chassis stability and body control. High-speed compression deals with sudden, sharp impacts like potholes, curbs, or landing jumps. Adjusting this fine-tunes how harsh or forgiving the suspension feels over big hits.
When you turn the adjuster clockwise (in), you are increasing compression damping by reducing oil flow. This stiffens the suspension, giving more resistance to movement. When you turn the adjuster counter-clockwise (out), you decrease compression damping by allowing more oil flow, softening the suspension and letting it move more freely.
Fine-tuning compression is all about balancing comfort, control, and traction. If the compression is too soft, the bike may feel plush, but it risks bottoming out on big hits, diving too much under braking, or squatting heavily under acceleration. If the compression is too stiff, the suspension resists movement too much, leading to a harsh ride, loss of traction on rough surfaces, and potential rider fatigue. The sweet spot depends on your riding style, weight, terrain, and motorcycle setup. Track riders may prefer firmer settings for stability, while street riders may want a more compliant setup for comfort.
Imagine you’re hitting a bumpy corner. If your compression is too stiff, the shock won’t absorb those bumps properly – the tire skips across the surface, reducing grip. If it’s too soft, the suspension collapses into its travel, making the bike unstable and imprecise. The right compression setting allows the suspension to absorb bumps while keeping the tire planted and the bike composed.
Compression damping is one of the most powerful tools in dialing in your suspension. By understanding what it does and how to adjust it, you can transform your motorcycle’s handling, comfort, and confidence. If you’re not sure where to start, always begin with your manufacturer’s baseline settings, then make small adjustments – one or two clicks at a time – and test ride to feel the difference.
At MotoTuned, we help riders set up their suspension for their unique riding style, weight, and terrain. If you’d like a custom baseline suspension setup that takes the guesswork out of the process, check us out at mototuned.com.au.
