"Creak" under braking?

[Lonnie Utah]

When I apply my front brake, I hear a distinct sound coming from around the stem/headset/fork area of my bike. I would describe it as creak/clunk/pop (it's not really a pop, if it is, it's a SLOW pop (if that makes sense)). I also hear it sometimes when climbing out of the saddle. I can sometimes (rarely) reproduce a similar noise (it's not as loud) when I push down hard on the handle bars (when off the bike). Given these three things, I'm fairly confident in saying it has something to do with the transfer of weight to the front of the bike. It's been going on less than 1 week (or at least only became noticeable in that time frame). On my last tune up at the LBS they said the steerer was way too tight an they loosened it a bit. That was maybe 3-4 weeks ago.

This noise was confounded by a BB/drive train click/tick that I "solved" by removing and cleaning/re-lubing the pedals/cranks/BB. That one I could feel in the frame (it resonated up the down tube) at a specific point in the pedal stroke.

Ideas?

Thanks in advance,
L

 

[hd reynolds]

I always say that the weak link in an A-Head style stem system is the part just below where the stem clamps on the steerer - specially on an aluminum steerer. Ít won't hurt to check if the steerer isn't cracked.

 

[Lonnie Utah]

I always say that the weak link in an A-Head style stem system is the part just below where the stem clamps on the steerer.

Ok Stupid question. What's an "A-head style stem." My assumption is the oppsite of a quill stem.

L

 

[John M]

Ok Stupid question. What's an "A-head style stem." My assumption is the oppsite of a quill stem.

L

He means the typical threadless type of headset/fork/stem configuration that almost all newer bikes have. The "A-head" refers to Dia-Compe's brand notation that they gave to the threadless non-quill headset when they introduced it several years ago.

 

[Lonnie Utah]

Thanks guys, that looks like a simple check.

Any other ideas?

L

 

[ScienceIsCool]

I second the idea that your fork warrants a very close inspection. Creaking is usually two pieces of material rubbing against one another under a fair amount of preload. A cracked steerer or crown would fit the bill.

John Swanson
www.bikephysics.com

Thanks guys, that looks like a simple check.

Any other ideas?

L

 

[John M]

Thanks guys, that looks like a simple check.

Any other ideas?

L

I would suspect a slightly loose headset. Probably the shop loosened it a bit too much. Try this: Lock the front brake and then rockthe bike front to back to see if you can reproduce the clunk. If so, it would suggest a loose headset.

 

[Lonnie Utah]

SOLVED! Kind of. It seems that the creak is being caused by the whole fork moving in the frame. Ok, now what? LBS to tighten it up? I'm assuming it's not really good to ride it in this condition.

L

 

[Lonnie Utah]

SOLVED! Kind of. It seems that the creak is being caused by the whole fork moving in the frame. Ok, now what? LBS to tighten it up? I'm assuming it's not really good to ride it in this condition.

Bump! Anyone?

 

[Lonnie Utah]

2 mins and $0 at the LBS and I'm back in business.

L