What type of clunking goes away with rain? (!)
 

Hi,

I have a number of bikes but had an interminable problem with a knocking/clunking noise that occurred when out of the saddle and applying considerable force via the pedals.

Over a considerable amount of time I sought I advice and checked everything. I swapped the pedals over, tightened the chainring bolts, checked the seatpost, and everything in between.

As it seemed to be coming from the BB area and sounded very much like a metal on carbon (frame) issue. I took it to my local LBS and managed to get them to refit my 68mm English threaded BB and apply loctite.

Nevertheless, the noise didn't go away and I became resigned to the fact that I, for the first time in decades was going to have to lump it or like it.

The curious thing however, is that last weekend we got caught out in torrential rain and lo and behold the knocking/clunking noise simply disappeared over the duration of a coffee stop!

Now I know my riding experience tells me just to get on with things and enjoy a noiseless bike but ... it's got me wondering as to why a large amount of rain has cured the noise.

I've been cycling for donkey's years and never had this occur before!

Can anyone give their penneth worth as to what it may have been and why a load of rain has cured it, please?

Ensure the quick releases (if so equipped) are tight and the hubs are centered and seated in the openings.

Keep an eye on it; the noise will return once everything dries out. The rainwater provided a temporary "lubrication" of sorts which has quieted the noise. I hesitate to use the term "lubrication" because water isn't a good lubricant at all, but in this case it has quieted the noise if nothing else.

It could be the BB bearings.

Just know you likely won't enjoy the lack of noise long. The water didn't cure the noise, it has masked it. If this bike is worth anything, I'd be doing an overhaul of the BB and hubs at the minimum.

Rim brakes? Wheel rim is warped and scrubbing the rim brake. Rain gets the rim wet and it goes away. If this is something you only experience when putting out some power then still might be the same thing and your rims are warping just enough to scrub the pads. Wet simply lubricates them and you don't perceive it.

Possibly you might need to have your wheels checked for true and proper spoke tension.

Is the drive side crank arm a single piece or is there a joint holding the arm proper and the spider together? That joint can make a noise, particularly under heavy load. Rainwater could get in there and maybe reduce it.

Otto

I'd replace your bottom bracket.

Check the chain and be sure every link pivots freely. If any link was overtightened after removing links and either inserting a pin (Shimano) or quick link, there may be a slight hitch. Water can temporarily make a dirty or stiff chain feel smoother, but the problem returns after everything dries.

Thanks for all the replies. Much appreciated.

Went out again in the rain this morning and not a sound!

Prior to the ride the other day when it all went quiet, I had greased where the hubs make contact with the frame, as it was literally the only thing I hadn't checked or attempted to alter.

The problem is that for the first hour of the ride, the grease made no difference, the knocking was ever present on sprints and hills. It was only after the rain that it went completely silent.

There was no hint of noise again today.

The BB was replaced when my LBS used the loctite to "fill" any gaps in the thread on the BB, so I'm not sure it's the BB bearings.

The wheels are Bora Ones and only 9 months old but I do regret changing from my beloved C24s. Maybe the hubs aren't right?

When I built the bike the new chain did have a stiff link but I flexed it back and forth and that did seem to the trick. The cassette is definitely secure and you'd imagine wheels wouldn't flex to that extent that there'd be a knocking at this stage. I'm only about 74Kg!

Other than that I'm at a loss. It's definitely more of a deeper click verging on a clunk. The sort of thing that sounds like metal on carbon fibre.

I installed everything from new myself and the parts are only about 9 months old. The crankset is a standard Shimano Dura-Ace compact and has been checked over by my LBS.

I did wonder if it was the Di2 junction boxes rattling around when I rock from side to side but it only happens when I'm applying a lot of pressure. Otherwise they don't seem to be heard.

OK, one more longshot... which I experienced...

Check the rear wheel spoke crossings. Tweak 'em together and feel or listen for any stiction and noise.

I encountered that with one wheelset with black spokes -- dunno if the spokes are painted, enameled, coated in plastic or what. But I kept hearing and feeling a sort of clunking noise for weeks. Overhauled the entire bike -- every bearing, hubs, BB, even the headset. No help. The noise was worst when I really put pressure down, or stood to pedal.

I noticed the noise wasn't there on wet days. That seemed to indicate something sticking.

I checked the chain links. All were fine.

Then I squeezed the spoke pairings for each crossing and, on the rear wheel, felt some stiction. I smeared some soft wax between my fingers (leftover unburned wax from a scented candle -- very soft) and smooshed it between each spoke crossing. Problem solved. I redo it once or twice a year, depending on the weather and how often I ride that bike.

I've had a similar issue once before, but with a cheap machine built rear wheel replacement for an errand bike. The aluminum spokes were larger in diameter than most, and for the first few weeks the stiction would produce a distinct pinging sound. As it wore in the noise stopped.

But the black spokes on that particular wheelset didn't make a metallic pinging noise. It was an odd clunk that I could hear and occasionally feel when standing to pedal.

Like I said, longshot but worth checking out. Try some wax between the spokes, see what happens. Some folks use oil or grease but wax is less messy, don't run off and lasts longer.

After putting about 3000 miles on my bike, a click developed at every turn of the crank when I was pushing hard. I was convinced that the click came from the bottom bracket, as were a number of LBS mechanics. Then one very experienced mech (in about a minute) diagnosed the cause as a poorly assembled fork/headset. I was amazed.

Not enough grease on the pedal/crank interfaces (threads and contacting flange)?

Otto

Yes, a friend said this could be the root cause. I've checked the spoke tension and it seems good but I will try grease on the intersections and where they meet the hub.

Thanks everyone else as well. I will re-grease the pedal threads and try another pair just in case. Although I must admit I've tried this before.

One thing I have experienced that was similar, just in case it helps someone else, is a similar noise that eventually turned out to be an integrated handlebar/stem that had cracked on the underside!

Every time I got out the saddle, I was tending to pull on the handlebars and eventually I checked them out and the stress had caused them to a crack. Not good!