Annoying squeak

[dddd]

Originally Posted by David Kirk

So it's got a Ti seat tube and it looks like you are running a clamp-on campy front der......I know it would sound nutty but pull the der off, clean the seat tube and der clamp well, put a light coat of grease on the inner surface of the clamp and bolt it all back in place.

And then enjoy the quiet.

dave


P.S. I could be wrong but this has fixed many mystery noises on those bikes.

I would maybe test that theory with a drop of WD40 first, seems like possibly a lot of unnecessary work on a bike that will never suffer corrosion on the seat tube.

[David Kirk]

Originally Posted by dddd

I would maybe test that theory with a drop of WD40 first, seems like possibly a lot of unnecessary work on a bike that will never suffer corrosion on the seat tube.

It's not corrosion that causes the issue - it's galling. Both the Ti seat tube and aluminum clamp gall easily and over time the flex of the system causes the two parts to rub off on each other. A drop or two of oil probably won't cure it and I don't really see undoing a single bolt and wiping things down and putting it back together as a lot of work. If it takes 5 minutes in total that would be a surprise.

Back in the day when we released the Legend Ti we had a lot of complaints out BB noise and it took a lot of time to figure out it wasn't the BB at all but it was the front der clamp. The Shimano adapter was the worst offender (being tall it rub on the seat tube more) but we saw it with most any der after some time passed. We issued a service bulletin at the time and the number of issues dropped to almost nothing.

If one takes the front der off and there are any areas where the seat tube has a smooth and glassy black area that's the source of the noise.

dave

[Mike Lopez]

Originally Posted by Ken Robb

What was Mom's name back then?

Hi Ken. Her stage name was Kimmy Stevens. Along with the previously mentioned band leaders she was also a member of a group called the Pied Pipers.

PM me with and address and I'll send you a sound bite and some amusing pics.

Happy new year!

[cgolvin]

Yesterday afternoon while on a boring conference call I was able to reproduce the squeak on the stand, and I'm 99% sure the RD jockey wheels are the culprit (one "I was right" birthday present for Old Potatoe).

Currently disassembled for lubrication, fingers crossed. Thanks to all my pals.

[dddd]

The pulleys, yes, especially the top guide pulley on Shimano Ultegra rear derailers with a dry ceramic bushing.

I've had to decide what to lube these with, since Shimano specifies these be run dry!

I've used pure silicone oil, which I thought would be friendly to the rubber seals and spin freely, and of course it worked.

[dddd]

Originally Posted by David Kirk

It's not corrosion that causes the issue - it's galling. Both the Ti seat tube and aluminum clamp gall easily and over time the flex of the system causes the two parts to rub off on each other. A drop or two of oil probably won't cure it and I don't really see undoing a single bolt and wiping things down and putting it back together as a lot of work. If it takes 5 minutes in total that would be a surprise.

Back in the day when we released the Legend Ti we had a lot of complaints out BB noise and it took a lot of time to figure out it wasn't the BB at all but it was the front der clamp. The Shimano adapter was the worst offender (being tall it rub on the seat tube more) but we saw it with most any der after some time passed. We issued a service bulletin at the time and the number of issues dropped to almost nothing.

If one takes the front der off and there are any areas where the seat tube has a smooth and glassy black area that's the source of the noise.

dave

Wow, that sounds like an example of what sometimes happens at the handlebar clamp or between the seat tube and seatpost, I've seen that burnishing there.
I wouldn't have expected a frame's seattube to flex enough to produce the creaking, but I guess titanium still tends to be a bit more flexible, and that is a high-stress location under pedaling forces.
I googled "galling" to see the breadth of it's definition, and I believe you are using the correct term to describe this sort of thing. I didn't know "galling" could arise with such different materials in contact with one another, but corrosion, pressure and friction could definitely come together to produce it in this location. I've even had a pedal creak until I more fully tightened the steel spindle into the alloy crankarm, and have used a drop of oil at many an old handlebar stem clamp.