Bicycle Mechanics - BB problem??

Today when i was on my MTb i found it felt funny. When turning the crank and pedal, it is not smooth. When i am in my lower gears i feel this sharp resistance when i pedal. It makes a small tinking noise. It is not consistant but it seems that it is one one part of the stoke. Once the in a higher gear i see that feels like the stroke is smoother. WHAT IS GOING ON??? Is it possible that this is only chain slip? I'm sorry if this is a bad discription. Not to sure how to discribe it. Thank you for you help.

Jared

Try this: shift to the inner chainring, then lift the chain off the chainring so you can rotate the cranks without interference from the chain. Spin them and see if they run "lumpy" and/or come to a halt quickly. If so, you've probably got a failing bottom bracket, and need to replace it.

If the crank spins smoothly and doesn't stop fast as if it has lots of resistance, then put the chain back on, shift to the middle chainring and the outermost cog on the rear, and rotate the cranks backwards while watching for any stiff links that make the chain "jump" as it goes around the rear cog. If it does that, you've got a stiff link in your chain, which can often be fixed. Refer to Park Tool's site for a guide to removing stiff links: http://www.parktool.com/repair_help/FAQtchan.shtml

http://www.parktool.com/images/TTOL/chain-tightlink.jpg

I did not see any stiff links. BUt the crank had a but of grity feel to it as i turned ti with out the chain on. it spun freely for a while and slowly came to a stop. any ideas?