my bike is around 5500 km and had done the first oil service. the problems with the bike are when i down shift to gear 3 or 2 while holding clutch, the gear doesent go down. i have to release clutch a little bit, then gear goes down. next one is when rpm is above 3000 or 4000, i shift gear from 1 to 2 or 2 to 1, then a big ban sound from gear box. is something wrong with my transmission??? thanks!