Hi thanks for your reply, And ok I will keep that in mind about the intro. I have checked the front sprocket today and it is in good serviceable condition, the chain is new and also lubed and the rear sprocket is good too. when i removed the front sprocket cover, put the bike into 1st gear on the stand... i noticed the noise was actually coming from behind the sprocket, i don't know if the shaft that the sprocket sits on is damaged but it seems to be ok as there is no movement in it and no signs of leaks. The wheel is aligned fine and also spins true. i have a bad feeling that it could be the gearbox on its way out after only 24000 miles. Thanks again.