Hi folks! I ride a single speed freewheel and noticed a knocking/slicking noise when pedalling hard. It is quite frequent and cannot be heard when im coasting. I had originally thought it was the bottom bracket so replaced that, took apart the entire bike, cleaned and degreased. Doesn't seem to have gone away! I've just replaced the pedals and can still hear it.

Frame is in good condition and doesn't seem to be damaged so I think it might be the crank arms or chain. The back wheel was recently replaced with a freewheel.

Any thoughts/advice/ideas?

Same standing up as sitting down? Could be seat rails.

I have also had quick releases click/chirp. Check your chainring bolts.

Is your chain too tight? The ideal tension is no tension; the chain should be able to be moved up and down 1/4-1/2" at the tightest spot in the crank's rotation. You may need to turn the crank a couple of turns to find the tight spot since both the chainwheel and cog bot have some runout; you will have to find the tightest spot.

Is it a Shimano single speed freewheel? They pretty much all knock a bit. On mine, I have found that when the clunking starts all I have to do is back pedal a bit and it stops (most of the time). If you really can't tolerate it, you could invest in a higher quality freewheel like the White Industries ENO.

I had loud popping and clicking noises in my road bike. Went crazy until I swapped the rear wheel with a spare and that fixed it. Took apart the offending hub and it is all pitted in the cone. That was causing clicking/grinding noise in the hub that was amplified dramatically by the frame. I bet it's your hub.

Chris