Bicycle Mechanics - Pedaling Sound! Help

I've been noticing a weird rubbing/grinding sound emanating from my drivetrain when I pedal. I just adjusted both derailleurs, with an experienced mechanic watching over me, so I don't think that the gearing is the issue. It seems to happen every half stroke, on both pedals, and is much louder when I'm putting lots of force on the pedals, such as uphill. I'm thinking that it might be a bottom bracket issue, maybe something with the bearings. Any advice or remedies? Any help is appreciated. Thanks!

It's unlikely to be both sets of bearings in the pedals, especially if the sound started from both sides at the same time.

Could be signalling the onslaught of breakup of the BB bearings or maybe the retainer (if you have one that is). That would correlate with the sound being related to force on the cranks.

Have you oiled your chain lately? It could be as simple as a dry chain or you lubed the chain but the lube didn't get inside. If the sound is sort of a wirrrrr or wooooosh sound on every power stroke? Take off the chain, check that it is not worn out compleatly, clean and lube, reinstall. Go for a ride! A quick way to check for a warn chain is to, get it on the big front chain ring, pull the chain forward and see if you can see a full tooth. If you can...the chain is worn out. Your LBS will check the chain for you also, especially if you are about to buy a new one.
Good luck

Have you oiled your chain lately? It could be as simple as a dry chain or you lubed the chain but the lube didn't get inside. If the sound is sort of a wirrrrr or wooooosh sound on every power stroke? Take off the chain, check that it is not worn out compleatly, clean and lube, reinstall. Go for a ride! A quick way to check for a warn chain is to, get it on the big front chain ring, pull the chain forward and see if you can see a full tooth. If you can...the chain is worn out. Your LBS will check the chain for you also, especially if you are about to buy a new one.
Good luck
Nope, it's definitely not the chain. I just cleaned all the gunk off of it and lubed it nice n' shiny about a week ago. And I'm not riding in any heavy mud or dirt, so it hasn't picked up too much stuff. I'll check it for wear too, but I don't think that's the case either, because the chain is only about a year old.

If you have a tapered BB, make sure your cranks aren't coming loose. If there is any play in them, on either side, it can produce some funky sounds. Sometimes it is a 'clunk' and other times a 'kadink', but it will sound worse under force.

If it was happening on just one pedal stroke I'd be betting on a chainring problem - either bent/warped or trouble with the spider.

Even with it hapening on both strokes this might be your problem.

It doesn't take much bend in a chainring to cause a regualr chain rub on the F/D. Firmly support the bike off the ground and then look straight down through the front derailleur cage at the chainwheel. Give the pedals a spin and see if the chainwheel wobbles. You should also, as noted above, check for play in the BB and pedals.