Originally Posted by carfreefamily

This noise is driving me crazy. It's on my 1952 Raleigh Superbe Sports Tourist. When I'm pedaling with steady pressure, no noise. If I suddenly accelerate, there is a loudish "clonk" sound. Sometimes it's a single clonk, sometimes there is a quieter "thuk, thuk, thuk" as I pedal.

I associate the noise on another bike with a loose saddle clamp - for a long time I thought it was a bottom bracket noise, but it was the saddle. That's not it.

I tightened my cotter pins and checked for play in the bottom bracket - not it.
The crank is not hitting the kickstand.
I retightened everything on the chaincase.
I adjusted the chain to make sure it wasn't too tight or too loose.
I tightened the rear axle nuts - slightly - I recently overtightened and stripped a nut on another bike.

I can't think of what else to try. When the bike is parked, if I press down on the pedal, it makes a quieter clonk. In order to get it to make the noise again, I have to spin the pedal around and press on the non-chainring side and then the chainring side to get it to make the sound again. Mostly, it's pressing on the chainring side that generates the noise. It certainly sounds like it's coming from the area of the rear hub.

Any ideas? I'm holding off on my longer rides until I solve it.