Mysterious clicking once per crank rev

chrisaonabike

Apols in advance, but this is another one of my speciality 'wtf is that weird noise' threads.

You may remember my chain catching when rotating pedals backwards thread. Hopefully this one will be a bit easier.

This is a very audible, distinct click - it occurs:

- only when I'm pushing on the pedals (and the click is louder the harder I'm pushing)
- exactly once per chain ring revolution
- regardless of whether I'm in the big or the little ring
- when the drive-side pedal is more or less at the top (so just as I start to push on the pedal)
- almost all the time, although it was intermittent to start with
- whether sitting or standing (so not a seat-post or saddle creak)

It started happening on the very first ride after the Prudential Swim London 100 (86) back in August. It was occasional and not as loud then; now it's nearly all the time, loud and getting louder. Sometimes it's now a double click, in fact.

Bike is a 2012 Defy comp, two years old, about 7000 miles since new.

Bloke in a LBS said "ah yes, bottom bracket's gone", quite confidently.

Sound right? Any other suggestions? It's driving me crazy now, so I want to get it sorted.

slowbike

Could be BB
Could be chainring bolts
Could be Pedal spindles
Could be cleat
Could be shoe

nickellis

You mentioned the drive-side crack being at 12 o'clock. Is it the end of the FD cable poking out to the right and clipping the crank arm on its way past.

My bike did this, and it took me months to work it out. A quick bend (or clip) and Robert is your mothers brother.

ElectronShepherd

In addition to the things slowbike mentions:

one or more chainring bolts loose
cracked frame

If you unclip one pedal, but still pedal hard with the connected pedal, does the click go away? If you put on soft-soled shoes and ride the bike normally (as normally as you can with flat soles on clipless pedals), so you still get the click?

chrisaonabike

nickellis wrote:

You mentioned the drive-side crack being at 12 o'clock. Is it the end of the FD cable poking out to the right and clipping the crank arm on its way past.

A truly brilliant idea, as I thought myself when I had it! But no, the FD cable end is short, pokes straight up, and goes nowhere near the crank.

I so wish it had been that...

Re the other answers.. I've just checked the chainring bolts, and they're tight as tight can be.

I'll check the pedal-related possibilities later, but the cleat bolts are tight.

Really hope it's not the frame, I've had no crashes.

Ben6899

A few clubmates did RL100 and ended up submerging their BBs at some point along the route. In most cases, and in these cases, that'll be enough to necessitate a BB service.

letap73

Wheel QR tightened properly or possibly even play in one of your wheels.

chrisaonabike

Ben6899 wrote:

A few clubmates did RL100 and ended up submerging their BBs at some point along the route. In most cases, and in these cases, that'll be enough to necessitate a BB service.

Yes, my BB was submerged quite a few times.

chrisaonabike

letap73 wrote:

Wheel QR tightened properly or possibly even play in one of your wheels.

Doubtful, given that the click is always once per chainring revolution.

Appreciate the suggestions so far, guys, many thanks.

defycomp2

Cadence sensor? Certainly my wheel magnet gives a "click" against the sensor when on the stand, so maybe a magnet on the crank is doing the same for you.

chrisaonabike

DefyComp2 wrote:

Cadence sensor? Certainly my wheel magnet gives a "click" against the sensor when on the stand, so maybe a magnet on the crank is doing the same for you.

Another good idea, none present.

slowbike

My clicking was a pedal spindle - easily tested by swapping pedals on from another bike ...

But it could equally be the BB - I'd changed mine before finding out it was the spindle oh well - it had done a good few thousand miles in my ownership and I don't know how many before then ...

slowbike

Could be your joints .... checked your knee recently?!

chrisaonabike

Slowbike wrote:

Could be your joints .... checked your knee recently?!

LOL cheeky sod

darkhairedlord

crack in the drive side chainstay where it meets the bottom bracket. :shock:

or just press in a BB set and hope for the best

chrisaonabike

Right, so I put my old pedals on (flats one side) and went for a ride in trainers - no click at all in several miles, even going up a steepish hill.

So that's the BB ruled out, I think, which is good news. Came back, put my normal shoes on, set off again clipped in. Again, no click. That's the BB and the shoes ruled out, so which pedal is it?

I put the original drive side pedal back on, and set off, expecting the click to return.

Nope.

Hmm, I thought. Left pedal back on, all back to the way it's been for months... but... no click :shock: . Blissful silence.

So, not the BB, not the shoes, and taking the pedals off and putting them back on makes the click go away.

Does that make any sense to anyone?

Anyway, I'll see how it goes - thanks for all your suggestions - I wouldn't have thought it might be pedals (they're Shimano M520s, only 4 months old), so you guys have saved me the expense and faff of getting the BB replaced. Cheers

I learned one other thing - I can't keep my feet on flats any more.

baznett

My first thought on a clicking noise every revolution is to always re-grease pedals and go from there, 8 times out of 10 this is the common problem.

Guernsey Donkey

Since they are double sided pedals, you did check both sides of both pedals?

(Don't ask how I know this but it took me months to sus' that it was only one side of one pedal that was clicking!)

Ben6899

Pedal threads can get dirty from time to time. Removing pedals, cleaning threads and reinstalling is often a sure fire way to cure a pedal click.

slowbike

ChrisAOnABike wrote:

I wouldn't have thought it might be pedals (they're Shimano M520s, only 4 months old)

My new pedals - M540's - required a bit of grease after just a couple of months ... it wasn't difficult to do ...

wilshawk

ChrisAOnABike wrote:

letap73 wrote:

Wheel QR tightened properly or possibly even play in one of your wheels.

Doubtful, given that the click is always once per chainring revolution.

Appreciate the suggestions so far, guys, many thanks.

the fact that it is once per revolution doesn't neccessarily mean the problem is around the drivetrain, it may just mean that at a certain point in each revolution there is strain on a certain part of the bike which causes the click. Check the Quick Releases are not done too tightly and the wheel is centered properly.

chrisaonabike

wilshawk wrote:

the fact that it is once per revolution doesn't neccessarily mean the problem is around the drivetrain, it may just mean that at a certain point in each revolution there is strain on a certain part of the bike which causes the click. Check the Quick Releases are not done too tightly and the wheel is centered properly.

Yes, fair point. Cheers - tho as I said above, the clicking does seem to have gone away since I took the pedals off and put them back on again.