I've been commuting locally around town in my Novara REI IGH (SHIMANO 7speed). One day I decided to carry a heavy load (around 20-25 pounds on my pannier rack and I had to jump off the curb due to an emergency. My bike pounded the pavement hard from jumping off the curb. Next, I started hearing a low grinding noise from the IGH. I ignored the noise and three days later, the grinding noise became louder and louder. I stopped riding this bike and switched off to my fixed gear. Anyone who has a IGH experienced such a noise from the IGH? What can be wrong with it since I can see the gears inside from my naked eye. Please help!