"Clank" noise on the second crank rotation!

[Bongo Bill]

Good evening all

I have a feeling there is an obvious answer to this question but please be patient with this enthusiastic but inexperienced cyclist!

I ride a single speed road bike. A few weeks ago I had a new Chris King bottom bracket installed to go with my Truvativ/Sram Omnium crank. I purchased the bottom bracket while I was in the US recently as the Chris King GXP compatible ones are not too easy to get here.

Anyway...all was fine for a couple of weeks. However when I now pedal & push down I can feel/hear a "clank noise" seemingly from the crank which usually happens on the second rotation - if that makes sense. The noise can come from either the left or right side and seems to be from the area of the bottom bracket. I thought it might be a stiff link on the chain but I could not find any and I do keep the chain well lubricated with Finish Line Wet.

The LBS that fitted the bottom bracket for me are no longer in business sadly as they closed a week after the work. If the bottom bracket is faulty returning it would be a problem as I bought it in the US.

So, would anyone care to offer a diagnosis as to what the problem could be? I would not feel too confident taking off the bottom bracket myself so perhaps a visit to another LBS might be imminent.

 

[accountantpete]

A guess would be that the cup/cups have worked slightly loose. - I had a similar problem with my Campy UT.

I think you need a special tool to tighten these (£30 per the interweb) so a trip to the lbs may be in order.

 

[Big John]

Noises are a bugger to pinpoint sometimes. It could be the bottom bracket but I'm told Chris King are the dogs do da's so I strongly suspect, unless your lbs fitted it wrong, the BB is fine. This leaves the pedals. Could be something as daft as that. Or maybe one of the bolts has somehow come loose.

If you've got a workstand then hoist it up and get your ears close to the action, although turning the cranks by hand isn't the same as turning them with the legs. I usually find a process of elimination works in the end.