I've been riding a cheap bikesdirect single-speed bike regularly for 2-3 months with no real problems. Today I was going up a moderate hill and my cranks/bb (I think it was one of these) made this crazy noise over and over. I was standing up and putting a lot pressure on the cranks b/c I was going up the hill. It sounded and felt like a bike that was slipping out gear, except that I have no gears. The noise/clicking/event happened 3-4 times while I was going up the hill. I got off and spun the crank w/ my hand. No noise. Walked the bike to the top of the hill and rode the rest of the way home. I'm assuming it was the added pressure I put on that area of the bike that caused this.

I haven't fully inspected yet, but I will tonight. Do you guys think that the cranks are loose or that something f'd up is going on? I'm no bike mechanic expert, but I'm competent with tools and the like. Yes, I put the bike together w/o LBS support, and I haven't had a pro tuneup on the bike except for having the wheels trued when I first got it.

Any thoughts would be appreciated.