It’s a key component, but how do gears actually work?
We ask the questions that beginners are dealing with and get answers from the experts
STUART HARWOODHOPE, TECHNICAL LEAD AT THE BIKE PROJECT “Gears allow the rider to maintain a comfortable and consistent pedal stroke over varied terrain. This makes tackling steep inclines, fast descents and maintaining speed over flat distances a doddle meaning you expend energy efficiently and, most importantly, enjoy your ride. Gears are selected using a shifter, located on the handlebars. When pressed, a specific amount of cable is pulled causing a mechanism called a derailleur to move the chain between different toothed rings. On the back wheel these are called ‘sprockets’ with chainrings at the front between the pedal arms. It’s up to the rider to find the optimal ‘ratio’ (combination of front chainring and rear sprocket) depending on the terrain. The amount of cable the shifter pulls is the same for every press and is equal to the space between each of the rings. This keeps everything perfectly aligned and allows the gears to change smoothly when pedalling. Derailleurs are also limited in how far they can move the chain, which stops it dropping off. The rear one also serves to keep the chain tensioned for the finish line sprints! Always remember to pedal when changing gears and try to avoid ‘crossing the chain’, that’s riding in the largest chainring and largest rear sprocket at the same time.”
In response to Covid-19 The Bike Project is providing Virtual Dr Bike maintenance online sessions to keep the public cycling during the crisis: thebikeproject.co.uk
DAVID BARNES, BIKE SPECIALIST WYNDYMILLA.COM
“The gear ratio is defined by the relative size of each sprocket. Moving to a larger chainring and/or a smaller cassette sprocket increases the gear, meaning a higher wheel speed for any given pedalling speed. A lower gear does the opposite; reducing the speeds and required effort to pedal any given cadence. The larger front chainring is hardest – great for when you’ve built-up speed on a flat road or for going down hills. The smallest ring is best for going up hills. The reverse is true for the rear sprockets – the smallest being the hardest and the biggest being the easiest. You’re looking for a gear that allows a natural pedalling cadence that feels comfortable and sustainable. High speeds and down hills will require a larger gear, uphill and slow conditions will suit the lower gears on the bike. If you’re struggling with running out of gears at the extremes then it’s likely that the ratios on the bike are not appropriate for where you’re riding or your fitness. Pay attention to how frequently you find yourself in the lowest/highest ratio. Installing a cadence sensor can help you track the data over a longer period and quantify how fast you’re pedalling.”
“A GEAR THAT ALLOWS NATURAL CADENCE WILL FEEL BOTH COMFORTABLE AND SUSTAINABLE”