Hi guys, about a month back i purchased a Polygon Heist 4.0 and I thoroughly enjoy my rides whenever i go cycling. It sports a Shimano Alivio groupset. One thing i noticed is the faster i go, the harder bumps on the road have an effect on my bike, and recently a simple bump threw my chain off the gear it was and it fell to a smaller gear, and i lost speed after being unable to pedal. *insert disappointed face*. Something loose perhaps?