BENOIT CAPOSTAGNO from Science to Sport in Cape Town jumps on board this month to talk about your body and what it goes through while racing
All the disciplines within mountain biking expose the rider to continuous vibrations and impacts caused by the terrain. These vibrations are then dissipated by the soft tissues of our bodies and the additional muscle activity required to absorb these vibrations can (affect the) ability of our muscles to propel the bike forward. The suspension system on your bike, whether it is a hardtail or a Full Sus, is designed to mitigate the effect of the vibrations and impacts. Mountain biking is a progressive sport, and the technological advancements associated with the sport are frequent. Cast your mind back a few years when we were debating wheel size, the number of gears and chain rings on our bikes, as well as the cost (energy) to benefit the ratio of rear suspension systems. The variety of XCO tracks in the National and World Cup XCO circuits and XCM routes mean that one bike may not be the best option for all courses. Tracks that have a large amount of climbing may be best suited for a hardtail, where improved climbing efficiency may outweigh the benefits gained while descending on a full suspension bike. The more technical courses may best suit a full suspension bike and there is definitely an increase in technical tracks in modern day races. Suspension systems on mountain bikes are designed to reduce the vibrations and impacts experienced by riders while they navigate technical terrain. Excessive vibrations will have a negative impact on performance by increasing the amount of energy required to propel the bike forward. Apart from driving their bicycles forward, the rider’s muscles will have to stabilise the rider and work against the vibrations. Suspension systems that best reduce these vibrations can add a performance benefit. Full suspension bikes (front and rear suspension) are associated with reduced vibrations and greater rider comfort, but require greater rates of energy expenditure to match the speed of front suspension only bikes. The extra weight of the rear suspension system will require a greater power output to accelerate uphill compared to a bike with front suspension only. In addition, the small compressions or bobbing can reduce the rider’s economy. Observations from the UCI XCO World Cup circuit shows that often bike choice will come down to course design. Courses with large amounts of climbing may be best suited for a hardtail, while the more technical tracks with challenging descents may require a full suspension bike. The “N+1 rule” applies to the professionals too. Your suspension system can be a key component of your performance and enjoyment. Select a suspension configuration that suits your riding preference, and service it regularly to keep it functioning correctly.