I have had my bike for about 6 months which I bought used. I trust the previous owner and wish to know what happened. He put new breaks and tires on in March of 2015. I went to s bike shop about a week ago and got my flat replaced. The guy then said that the tires needed replacing and my breaks. Maybe they just decided that it looked old because they didn't do anything they just said that. Is there a problem with my bike or is it fine?