Very strange noise coming from an apparently healthy bike.



To clarify: The original recording was done whilst riding the bike round the block to the front of our house. (I have since tried weighting the pedals with the bike stationary)


We have had the bike a year or two maybe, so not sure how possible or likely a manu' defect is now?
[the bike has spent most of its life wrapped in a blanket in the garage(which is very well insulated and dry) and then it gets brought out occasionally and put to use on some beachy/woody trails mostly.


I gave the spokes a little pluck when i was first debugging this, they all sounded good.
 
bobbynopedals said:
To clarify:  The original recording was done whilst riding the bike round the block to the front of our house. (I have since tried weighting the pedals with the bike stationary) We have had the bike a year or two maybe, so not sure how possible or likely a manu' defect is now?  [the bike has spent most of its life wrapped in a blanket in the garage(which is very well insulated and dry)   and then it gets brought out occasionally and put to use on some beachy/woody trails mostly. I gave the spokes a little pluck when i was first debugging this, they all sounded good.
You can ignore Hillrider. He's a troll. I'm betting it's either toasted bearings or a loose crank arm, neither of which would be a manufacturer's defect.
 
doctorold said:
I have listened again and I have to concur with others.  That has got to be a bottom bracket problem.
i think so too, happened to me once, very similar noise, mine was broken but i could still ride and the solution was a complete replacement,
 
OK, one more stupid wild-ass guess, and then I pass. Is it the left crank hitting the kickstand?

Or perhaps Colonel Mustard in the pantry with the candelabra?
 
No kick stand on it anymore I'm afraid, and this is on hold until tomorrow, My crank puller, which I haven't seen for a while, has gone AWOL, so I'm gonna roll down the LBS tomorrow and see what they say and pick one up.

My money is on the crank arms.
 
Clue, now that was a board game to reminisce over.

I thought Mrs White and Proffesor Plumb had a thing for each other beyond flirting.
 
Originally Posted by bobbynopedals .

No kick stand on it anymore I'm afraid, and this is on hold until tomorrow, My crank puller, which I haven't seen for a while, has gone AWOL, so I'm gonna roll down the LBS tomorrow and see what they say and pick one up.

My money is on the crank arms.
Smart idea, taking it to the shop. Doctor's normally don't make diagnoses over the telephone.
 
Well, the saga has came to an end... it was the BB bearings.some had completely shattered.

I've no idea how it could have been so tight and smooth with all them bits in there, but it was.


Thanks a lot for all the help, 'tis much appreciated.
 
Originally Posted by bobbynopedals .

Well, the saga has came to an end... it was the BB bearings.some had completely shattered.

I've no idea how it could have been so tight and smooth with all them bits in there, but it was.


Thanks a lot for all the help, 'tis much appreciated.
Hey, that was an easy one. For future, you can get a good feel of the BB bearings by just dropping the chain off the inside chainring and then turning the crank slowly with one finger on the crankarm. Bet if you had done that, you'd have been shocked by how "notchy" the bearings really were. I do this check every now and then, when cleaning or lubing the bike, as it only takes a minute.

It's even more revealing to turn the BB spindle without the crankarms. Last time I did that check, prior to changing BB bearings, the spindle would "stick" and virtually impossible to turn with the fingers. Just riding the bike on those toasted bearings, I really couldn't feel or hear anything wrong. But after pressing in a new pair of bearings, the bike did feel smoother.....and much faster of course.
 
"I've no idea how it could have been so tight and smooth with all them bits in there, but it was."

Ancient Chinese Quality Control secret!

The bearing balls must have been over hardened. In all the years I've wrenched on bikes from department store junk to pro level stuff, I've never seen shattered bearing balls.

Brinnelled, scored, pitted cups and axles, rusty guts, stripped axle threads, split crank arm bosses, bent ball cages...yes. Dry bearings ground to dust? Yeah. But, I've never seen bearing balls in pieces. That had to be some garbage steel and/or heat treatment.
 
Actually campybob, "shattered" probably isn't the right word to describe the state of bearings tbh.

It looked to me like one of the bearing had split, and one of the pieces was being ground into bits.


dhk2, I'll keep that method in mind, especially as I plan on looking after this new bike of mine properly.


Once again, thanks everyone.
 
You really need to recheck the steering and get the headset checked out to get to the bottom of this problem.