Click, Click , Bloody Click . . .

[goosander]

I frequently suffer a similar noise, reversing the chain helped for a while but it soon came back.  

I have found that after switching from Finish Line red (which worked well for my deraillieur bike) chain lube to the heavier/messier Finish Line green, the clicking noise occurs less frequently and usually goes away after lubing the chain.

Slightly OT - I'm surprised that some of you seem pleased with 3000 miles chain life from a PC48 chain and a rohloff, I would have hoped for much more as I used to get that mileage out of PC48's on my deraillieur bike.

[geocycle]

Might have solved the clicking....  Took the cranks off and aimed to remove the BB, but couldn't shift it and when really applying torque the eccentric moved.  NB when the eccentric rotated the securing bolts scored a channel in the EBB-be really careful when trying to move the BB in situ!  So, I removed the EBB clamped it in a vice and tried again -still couldn't shift the BB.  On the assumption that the click was therefore not due to any movemment in the BB I greased everything else up and refitted.  There was a bit of rust on the shell and the dents in the EBB looked a bit enlarged so this is my main suspect for the source of the click.  This would be consistent with the fact that the click went away briefly when the original chain was turned and when I replaced the chain. I'll keep you informed.

[stutho]

geocycle
What type of cranks are you using? The reason I ask is that Octolink cranks (esp. XT) are well known to creak, maybe you noise is coming from these? Alternatively it you think the noise is coming from the EBB / Frame interface it would be worth trying some PTFE tape (Pluming tape) around the EBB.

If I put my chain on upside-down it makes loads of noise the other way up it is almost silent.  Why? – No idea but the difference is huge.  The only explanation I can think of why the chain is nosier than on my derailer is that possibly I ran the chain too tight at some point in the past and it has deformed slightly. (I now run it very loose)

(For reference I use a SRAM P68 chain-5500miles; Blackspire DH chainring and Rohloff chain oil)      

[geocycle]

Thanks Stutho, I may try the PTFE tape idea if the problem re-occurs.  I am using a square sectioned spindle in thorn cranks.  It is possible that greasing these up may have been the solution. However, when I reversed the original chain and also when I fixed a new one the problem stopped for a few days before returning, which leads me to think it is something to do with the EBB.  At the moment the chain is quite tight but different tensions didn't seem to affect the irritating click.  I've now got a PC68 chain and I am using finish line green oil, the PC48 chain had only done 1600 miles and is now a spare.  

When you remove your BB do you leave the eccentric in place on the bike?  As I mentioned above this resulted in the EBB moving and some damage.

[stutho]

One more thought:

Another thing that might be worth a try is to remove the ebb and install it the wrong way round so the left is on the right.  When you then tension the chain you will find that the bolts should bite on a ‘fresh’ area of the EBB (remember that the thick side of the EBB should always point down)  

NB Long term it would be bad practice to leave BB in the wrong way round. So consider this a diagnosis procedure.

WARNING I have NOT tried this myself