The Decathlon Rockrider ST100 Mountain Bike Wheels are 26-inch in size and made of aluminium, making them lightweight and durable for off-road adventures. With a sleek black colour and front suspension, these wheels offer a smooth ride over bumps and rocks. The grip shifter and derailleur gears make for easy and precise gear changes, while the adjustable seat ensures a comfortable riding position. Perfect for mountain biking enthusiasts looking for a reliable and high-quality bike to tackle challenging terrain.