Scraping/Squeaking noise on recumbent stationary bicycle

I have a ProForm recumbent bicycle which uses magnetic resistance. I have used this bike for over a year w/ no problem. Recently, the bike began to make a squeaking/scraping noise. The pedals turn, but you can feel a little friction accompanied by a short metal-on-metal squeaking/scraping noise. I have stripped the bike of all of its coverings so that I could observe the magnetic wheel and other moving parts, but there is nothing that appears to be causing this noise. I oiled the hubs and other parts that looked like potential culprits, but the noise persists. Oddly enough, when I get off the bike and turn the pedals by hand, there is no noise. But when I climb onto the bike and pedal normally, the noise appears.

Any help would be greatly appreciated.