mysterious clunking sound

[weisan]

I wonder if you can help me diagnose a mysterious sound that has been eluding me ever since my new bike was built up. It normally happens during standing up on a climb, near the bottom stroke of the crank revolution, a dull clunking sound with a slight knock would come on. Not sure if it's the BB or the Ritchey clamp on the downtube, or the headset...I looked it over but couldn't find anything wrong....

first person to help me get to the bottom of this receive a mysterious gift as a token of my gratitude. you can rest assured it's a nice bike-related gift... :D

thanks!
weisan

[BumbleBeeDave]

The carrot and stick approach!

Were you on good terms with whoever built it up? My money would be on a bolt suspended down the seat tube with a length of fishing line. :rolleyes:

BBD

[David Kirk]

Can you make it happen by hitting the front brake hard?

Could the the fork crown race moving on the fork.




Dave

[Black Dog]

In the large ring with the drive side crank up? It could be the front derailleur cage knocking the crank arm.

[BobbyJones]

To eliminate the Headset, try over-tightening temporarily for a quick ride.

Similar issue last year that was driving me nuts- ended up being the headset but sounded like it was coming from the BB.

Tightened the headset "just a little more" than I thought it should be and solved the issue.

[mgm777]

Weisan-pal,

How are you?

I had a similar noise/problem a few years ago. For me it was a slightly loose bottom bracket. I took my bike to OldPotatoe, at his shop in Boulder. He removed the BB, regreased, tightened to proper spec, and voila, the clunking noise was gone.

Check-out this thread (deja vu): link to old thread (http://forums.thepaceline.net/showthread.php?t=46417&page=1&pp=15)

Hope your back is feeling better.

MgM

[Chousen One]

once this happened to me where a chain pin left a stiff link that I didn't notice. As it came around the chainring it would make a slight clunking that I swore for days was coming from my BB, then pedal, which I subsequently disassembled and regreased. Good luck!

[spamjoshua]

A spoke nipple suspended on fishing line, and hanging from the seat, down the seatpost, and running most of the length of a seat tube is a classic evil trick.

ha.

[chismog]

+1 for the crankarm hitting the FD cage.

+1 for disassembling the crank and BB, regreasing everything, tightening to spec (tight!) and putting it back together. I had a similar issue with Campy Record square taper on a Colnago MXL. Drove me nuts, I consider myself a good mechanic but I didn't seem to be able to solve the problem. A good LBS here did the needful and I never had an issue on that bike again.

You didn't say what sort of a bike this is, but remember that Italian BB drive cups tend to work loose because of the thread direction...

Hope this helps!
-C

[srice]

I have to agree with checking the tightness of the bb cups. I have a non-driveside cup that worked itself just loose enough to make a noise when I stood. 5 minutes and that one was fixed.

The hardest noise to diagnose was the machine screw holding the bottom bracket cable guide that was just a little long. It was touching the bottom bracket and when I was standing to climb, there was enough flex to create a horrible noise. That one took about a month to find.

[weisan]

PALS!

Thank you for all your suggestions. I will look into each and every one of them, including BBDave's cancellera-motor-bike conspiracy theory!

Keep the ideas coming, I will be working on my bike later this morning.

[skijoring]

Good idea to clean and check your skewers where they grip the dropouts on your frame and fork, Weisan-pal. :beer:

[AngryScientist]

Good idea to clean and check your skewers where they grip the dropouts on your frame and fork, Weisan-pal. :beer:

yes, this, debris on the mating surfaces of the QR could indeed cause a clunking sound.

also, didnt see if it was mentioned, but i'd remove, grease and torque the pedals down tight.

[SPOKE]

I wonder if you can help me diagnose a mysterious sound that has been eluding me ever since my new bike was built up. It normally happens during standing up on a climb, near the bottom stroke of the crank revolution, a dull clunking sound with a slight knock would come on. Not sure if it's the BB or the Ritchey clamp on the downtube, or the headset...I looked it over but couldn't find anything wrong....

first person to help me get to the bottom of this receive a mysterious gift as a token of my gratitude. you can rest assured it's a nice bike-related gift... :D

thanks!
weisan

Ritchey clamp on the down tube......what's this? Is this a Ritchey Break-Away frame?

[bambam]

Maybe try to rule out the pedals and shoes. Try different shoes on the same pedals to rules out cleat pedal contact. Then different pedals to rule out pedal bearings.

[Joachim]

also, didnt see if it was mentioned, but i'd remove, grease and torque the pedals down tight.

+1. Whenever I have clicking, clunking, ticking sounds, I always regrease the pedal threads first before I start to look at QR's, BB, headset, stem, handlebars and cassette lockring. Especially if it follows your pedal stroke.

[oldpotatoe]

I wonder if you can help me diagnose a mysterious sound that has been eluding me ever since my new bike was built up. It normally happens during standing up on a climb, near the bottom stroke of the crank revolution, a dull clunking sound with a slight knock would come on. Not sure if it's the BB or the Ritchey clamp on the downtube, or the headset...I looked it over but couldn't find anything wrong....

first person to help me get to the bottom of this receive a mysterious gift as a token of my gratitude. you can rest assured it's a nice bike-related gift... :D

thanks!
weisan

We start with the pedals...ride w/o cycling shoes...if still there, swap pedals....if still there, swap rear wheel.....if still there, swap front wheel......if still there, BB OVH.......

[thwart]

We start with the pedals...ride w/o cycling shoes...if still there, swap pedals....if still there, swap rear wheel.....if still there, swap front wheel......if still there, BB OVH.......I like that... the pro's systematic approach to tracking down noise issues... makes a lot of sense, and avoids unnecessary overhauls.

Like the time I did the BB when the sound was actually coming from a pedal... :rolleyes:

[oldpotatoe]

I like that... the pro's systematic approach to tracking down noise issues... makes a lot of sense, and avoids unnecessary overhauls.

Like the time I did the BB when the sound was actually coming from a pedal... :rolleyes:

"My BB is making noise"...is common. 85% of the time it's something else. Particularly on mostly hollow plastic bikes. Sound really resonates around in these. Mostly it's pedal/cleat.

[weisan]

"Out for a repair, please come back later" ;)

[Hawker]

Did you ever get to the bottom of this?

Fan blade hitting the radiator or CV Joint? :)

[Bob Loblaw]

What kind of bike? What's it made of?

[Louis]

A very easy test:

1) Remove front wheel.

2) Replace front wheel, this time tighten the QR significantly more than before.

3) Ride bike.

[weisan]

MgM-pal!!!

I know this is a bit of a stretch. But upon hearing the different suggestions, I went back and see if I could tighten the BB just a bit more. Well, as it turned out, that was all it needed on the non-driver side, that extra encouragement to take out the BB wrench and tighten that sucker up real good with sheer brute strength. It moved just a tiny bit like 2-3 degrees and that did it, the noise went away promptly on the next ride and never came back again.

I really appreciate all the various contributions. This is all in good fun. MgM-pal, I will be contacting you on a PM to collect your prizes. :D

Now if I could get the creaks to disappear on my Specialized Toupe 143 saddle... :confused: :o :p

[rwsaunders]

Now if I could get the creaks to disappear on my Specialized Toupe 143 saddle... :confused: :o :p

Sell the saddle and the noise will go away...ready for my prize.