What are the key features of the Decathlon Rockrider ST520 and how does it compare to other bikes in the Decathlon range?

The Decathlon Rockrider ST520 features a lightweight aluminum frame, 27.5-inch wheels, 100mm front suspension, and 24-speed Shimano gears. Compared to other bikes in the Decathlon range, the ST520 offers a good balance of performance and affordability, making it a popular choice for entry-level mountain bikers.