Rear Hub (?) Clicking Noise
 

Advice needed: I just got a ten-year-old, but like-new Specialized Langster, running it freewheel. There is a faint, occasional clicking sound seemingly coming from the rear hub. This clicking does not happen all the time! But when it does happen, it's when pressure is being applied to the pedals. The clicking cadence is faster than the pedal stroke, possibly wheel speed. I bought a new rear hub, greased all bearings, and the clicking sound still happens. I installed a new chain, and loosened/tightened the spokes; wheel is true except for a slight bump, but clicking still happens. It sounds like it's coming from the rear, but is it possible it's the bottom bracket? Is it the 1/8th inch bump in the rear wheel? Thanks in advance for any sage advice!
-Tom in Orange County CA

We are talking about when you pedal forward and not actually allowing it to freewheel.... right?

I might say you are just riding on a smooth and peaceful part of your route and are hearing the rollers engaging the cogs in the back. But seems like you are saying that the noise is not that fast.

I once had a speed sensor on the wheel adjusted real close to the magnet and on turns I'd hear it hitting the magnet as the wheel flexed.

Otherwise I really don't know.

I'm not sure what you mean by "running it freewheel".
The sound can definitely be coming from the bottom bracket or even pedals or loose chainring bolts or....
Assuming you have the luxury of time, try to change one variable at a time until the problem is fixed.
These little ticks and creaks can drive the rider crazy, but for the sake of science, it's always fun to find the smoking gun.

Yes, it only clicks when I'm pedaling forward, but when I'm pedaling, it doesn't always click. It's almost as if the clicking happens only when the internal pawls grab at a certain point on the hub. By "running it freewheel" I mean it's not a fixed gear. It's a flip-flop hub but I'm not a masochist :lol:
So far, I've replaced the rear hub and the chain. I suppose pulling out and greasing the bottom bracket is my next step.

Try the cheap thinks first, like removing the pedals, clean threads, grease reinstall.
Depending on the type of bottom bracket, it might be unserviceable, but you could at least remove, clean threads, grease, re install.
I assume the click could be coming from the cleats, so perhaps try riding around without cleated shoes.

Oh yeah... I also had a click I couldn't find for months that turned out to be a metal zipper tag on a bag hitting the rear brake caliper. It wasn't constant, but when putting a reasonable amount of power into the pedals, it was always there.

Make certain it's not a shoe lace tip or something else hitting your frame somewhere.

You mentioned when in freewheel mode. Does this mean you can disable the freewheel on that hub. What happens when you do disable the freewheeling??

It's a single speed with a flip-flop hub (there's a sprocket on both sides of the wheel; one is fixed, the other freewheel). If you spin the whole rear wheel around, it can operate as a fixed gear, which I do not do. I use it in freewheel mode, with cantilever brakes. I suppose I could try running the bike in fixie mode to see if that eliminates the clicking. It's definitely not a shoelace or a bag strap. What's confounding is that it sounds like it's coming from the rear of the bike.