Pinging or knocking heard from bottom bracket

[kovacsa]

Hey All, Without taking the bike apart, I was hoping to figure out what a knocking or pinging sound is due to. It seems like it's coming from the bottom bracket. It happens at the same point in my peddle cycle (although that point has changed over time). I suspect something is loose like a ball bearing or something is cracked.. It only happens when I'm peddling and there is load on the chain. Any ideas? Thanks!

Audio: https://vocaroo.com/i/s1bidFnmnnGa

 

[berty bassett]

Fwiw I think bearing noise is usually a bit haphazard and not at the same point
I would try -
Make sure you are not catching cable with shoe each time ( or catching anything )
Standing up to make sure not seat post
Putting hands right near steerer to try to eliminate any noise that might be handlebar related
If it still happens then head towards the crank - make sure chainrings are tight
Maybe wd40 on cleats and pedals ( be warned - makes it lethal to walk on tiles )
After that I would try the cups but it’s a bit of a faff
Good luck
O just in case - make sure it’s not a magnet on wheel for speed sensor catching

 

[kovacsa]

Fwiw I think bearing noise is usually a bit haphazard and not at the same point
I would try -
Make sure you are not catching cable with shoe each time ( or catching anything )
Standing up to make sure not seat post
Putting hands right near steerer to try to eliminate any noise that might be handlebar related
If it still happens then head towards the crank - make sure chainrings are tight
Maybe wd40 on cleats and pedals ( be warned - makes it lethal to walk on tiles )
After that I would try the cups but it’s a bit of a faff
Good luck
O just in case - make sure it’s not a magnet on wheel for speed sensor catching

These are great tips, thanks. I didn't know how to test the seatpost as someone also brought this up as being a possible cause.

What do you mean by, "try the cups"?

 

[Cycleops]

I think it would be useful to know what sort of BB you have, if you're not sure post a pic.

 

[kovacsa]

I think it would be useful to know what sort of BB you have, if you're not sure post a pic.

Shimano Octalink Here is my bike, https://www.bikes.com/en/bikes/whistler/2015. Must select Whistler 70 when on the site

 

[fossyant]

Make sure the BB is tight in the frame, or torqued up properly - what type is it (or bike if you aren't sure).

 

[kovacsa]

Make sure the BB is tight in the frame, or torqued up properly - what type is it (or bike if you aren't sure).

Thanks for this. It's for a hybrid bike, See bike details in above post

 

[fossyant]

Ah, I'd take the cranks off, loosen the BB cartridge and tighten back up - a bit of grease on the threads.

Then starts the process of finding the noise if that doesn't cure it. Check for flapping shoe laces etc - believe me, it happens

 

[Cycleops]

I'm afraid you need to do a bit of dismantling to check the components to find the problem.
You'll need a few tools, a 10mm Allen key (some use 8mm), a crank removal tool, a spanner and splined removal tool for the BB cartridge.
These videos might help you;


View: https://youtu.be/3poD05IeGpg


Then follow the advice above.

 

[Cycleops]

Perhaps before you start pull the cranks from side to side to feel for play in the BB. If you can move them more than just a fraction you might have found the cause of the knock. Then proceed as above.

 

[CXRAndy]

Shimano UN26 BB