Using The Body As Suspension
Managing forces requires riders to react to what is felt through their hands and feet. Undulating terrain makes it feel like the bike is either being pushing up and into the body, or being pulled away and dropping from beneath the body.
Riders can either relax and absorb, letting the bike do what it wants, or be strong and drive, making the bike do what you want it to.
Relax and Absorb
With relaxed muscle tension, the arms and legs are like soft suspension that allows free movement of the bike. The bike and body work independently of each other. As the terrain undulates, the riders head remains level while the bike moves beneath them.
A relaxed and centred body position allows the bike to move up and down freely, maximising stability and keeping pressure consistent. Allow your elbows and knees to bend and extend as the bike moves up and down beneath you.
Strong and Drive
With strong muscle tension, arms and legs are like stiff suspension that generate and release their own pressure, making the bike and body work together. When the bike dips or drops with the trail, riders lower themselves and push with hands and feet, pumping the bike. When the bike comes back up with the trail, riders stand tall and pull the bike upwards, actively absorbing impacts.
A strong and centred body position allows riders to weight or unweight the bike as the trail undulates. Grip the handlebars firmly and push or pull with both arms and legs to create or release pressure.
Being smooth is efficient. Efficiency means less fatigue, faster laps and longer rides. Trails dictate the best way to stay smooth and tell you whether it is best to relax and absorb impacts, or be strong and drive the bike.
Relaxing and absorbing impacts is a smooth and efficient way to ride slower trails. Slower trails have smaller forces and lower impacts on riders, meaning muscles can relax. Absorbing impacts uses less energy and helps you maintain speed over humps and bumps.
If a rider is too relaxed they may be overwhelmed by trail forces. Larger impacts can challenge body positions, cause a loss of balance, and can sap your speed through corners and technical terrain.
Being strong and driving the bike is a smooth and efficient way to control the bike when moving at higher speeds. Faster trails inflict greater forces and harsher impacts on riders, meaning muscles need to be strong. Hands and feet push or pull the bike to create and release pressure. This pressure can be used to pump and generate speed as riders drive the bike through corners or hop and skip through technical terrain.
If a rider is too strong and stiff they will not absorb impacts and the bike may bounce or deflect off obstacles, causing the rider to lose control. Staying strong uses lots of energy and fatigues you faster.
To increase traction, tyres need to transfer more force through them to the ground. When tyres are weighted, side walls bulge and the contact patch increases in size. More rubber on the ground equals more grip. To see the difference, stand over the front of the bike, compress the fork and watch how the tyre reacts to different amounts of pressure. Getting low, being strong and driving through directional changes help you increase traction and generate speed around corners.
Unweighted tyres have a smaller contact patch when compared to a weighted tyre.
Getting low, being strong and driving through directional changes help you increase traction and generate speed around corners. Slippery sections like those found on off-camber, rocky or rooty trails ask riders to be light and minimise the weight placed on the tyres.
Before entering slippery sections, find a place with grip, get low, weight the bike and create pressure. Just as the trail gets slippery, stand tall, unweight the bike and release the pressure. This helps riders to stay light and minimise the weight on the tyres until they are through the slippery section. When riders are light, they can relax and absorb impacts that would have otherwise pushed them offline and sapped their speed.
The feelings achieved by alternating between relaxed and strong riding techniques can be described as similar to what is felt on a roller coaster ride. As the roller coaster rises up and over a crest, you feel light, or relaxed, as your bum lifts from the seat. When the roller dips and travels through hollows, you feel heavy, or strong, as you are pushed down into the seat.
On the bike, riders use their body as suspension in order to control the pressure over rises, crests, and when grip is scarce; making themselves light and relaxed to absorb impacts, maintain speed and avoid sliding out on slippery sections.
Riders then make themselves heavy and strong by pushing into the bike, to generate speed and maximising traction through dips, hollows, and when grip is available.
Back-to-back runs are a great way to compare and contrast relaxed or strong muscles, as well as develop better feeling through the hands and feet. Feeling subtle differences encourages quick reactions and changes in muscle tension, helping to control forces and stay smooth.