screeching noise in bottom bracket There is a very loud screeching noise when i pedal hard on the down stroke. Be it moving off or climbing up a hill. It is not coming from the front wheel, which i originally thought came from brake rubs, because when the sound still arises when i put my bike on the trainer. i am pretty sure it comes from the bottom bracket and only arises when i pedal hard. if i am coasting at 30kmh, there are no sounds, but if i pedal hard to raise the speed, then the loud screeching noises will arise again. please help! thanks
With this level of information, the only good answer is to say,"Find a competent bike mechanic, and ask them to look at it."