Bicycle Tutor

Hi Alex. Great web site,
My bike is quite new, but I have ridden a lot last summer. Eventually I started hearing a noise when I pedal fast- kind of a whining noise on each rotation of the pedals. It doesn't seem to slow my progress, and I keep the bike cleaned and oiled per your tutorials. The noise does worry me, however. Any advice is greatly appreciated.
PS: I'm very happy to see how your site is progressing. I have used your tutorials to make various repairs and maintenance on mine and my wife's bikes.

Can you figure out where the noise is coming from? The first thought, if it's quite new is maybe that one or both of the derailleurs is slightly out of adjustment and it's causing the chain to grind against the gears. This is not uncommon for the cables stretching, so this might be a possibility.
Of course, the biggest thing is to figure out where the noise is coming from before we can say more.