Cockpit cracking noise

[sethschmautz]

So... I'm not really sure how long this has been going on, but I know that it has at least been going on since last fall when I landed off a small jump just in time to hit a downed tree. I went over the handlebars, and although I thought I had caused major damage, I ended up only having to retrue the front wheel, tighten the headset a few times and replace the tire.

This past spring I started noticing a cracking noise when hitting bumps or hitting my brakes hard. Last weekend I stopped at the bottom of a downhill and while waiting for my wife, found a small crack at the top front of my head tube. I immediately figured that I had cracked the frame and needed to fix or replace it.

Today, I pulled the fork and examined the inside of the head tube. No noticeable damage that I could see. It is certainly possible that it still exists and it is hidden by the headset, but there was nothing obvious.

Today I pulled the fork, cleaned and regreased the headset, cleaned the stem/steerer tube interface, cleaned, slightly greased, and torqued the stem bolts. (I also replaced my brake pads, but I think this is unrelated...)

It still creaks/cracks. I can even get it to do this by just standing in front of the front wheel and pushing down hard on the handlebars. I even swapped wheels with my wife's bike (which doesn't have this same cracking noise when I do the same things) and the nose persists. I'm starting to think that maybe this is something in the fork, the star nut, or the maybe the shims above the headset? I'm running out of ideas. Here is a video with the sounds that I'm experiencing when on the trail. Any help would be much appreciated.

Seth

https://photos.app.goo.gl/p4hCWsheKBQmHBe88

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[toast2266]

My money's on the csu.

[skaredshtles]

2nd the CSU diagnosis.

I had a basically brand new Fox 34 that started doing this - shop replaced the headset, then messed with some stem spacer or something, but the crack noise persisted.

I put on an MRP Ribbon coil and, voila, no more cracking. Took the Fox to the shop, had them send it back and they returned it with nice, new, shiny Kashima stanchions and a full-length steerer.

Let me know if you're in the market for a lightly used Fox 34 with new stanchions/steerer.

[Dee Hubbs]

CSU, Its a common problem with that generation of Pikes.

[sethschmautz]

Ah yes... What I'm reading in the interwebz seems to describe the problem perfectly. Most suggest that it is not life threatening, just annoying. Is this true or am I gonna die?

Also, there is rumor of a loctite fix and a company in Vancouver, BC that can do it. Anybody ever tried? If not dangerous, I'll probably just ride it...

Seth

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[mntlion]

remove the fork, and see if it still does it.

http://suspensionwerx.com/ excellent work

[sethschmautz]

Dave, I'm not sure if you are serious or joking? :-)

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[radam]

Green (penetrating/wicking) loctite. Get it in at the crown-steerer interface and crown-stanchion interface. It might work. I had one Pike that it 95% fixed, another that it only just barely helped. Good luck

[sethschmautz]

Thanks. I've got some on the way.

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[nortonwhis]

I'm confused, you cracked the frame and are wondering why there is a creak coming from the cockpit area?
I cracked a frame and the two rides I had on it after that i had after that had non stop creaks, new frame, creak gone.
My crack was right by the bottom cup, so maybe that made it easier to hear

Also you should never ride with a cracked frame, particularly up front, cos if that junction gives way at high speed you are completely and utterly fucked

If you're frame is fine and I misread, the CSU is prime candidate as previously mentioned. You can also check all your stem bolts as i have had creaks from there in the past.

[sethschmautz]

There is definitely still a hairline crack at the top of the head tube, but it might only be the gelcoat. When I saw the crack I immediately thought I had found the source of the noise.

After Toast mentioned the CSU I started doing some reading. Many mentioned loctite 290 as being effective. Not everybody has a 100% success rate, and the other thing that was mentioned for Pikes specifically was tightening up the top caps on each side and torquing then to 28Nm. I serviced my own Pike this year so I checked both. The air spring side was close but needed a little tightening. The damper side was very loose. I didn't have a 30mm socket, but I tightened it similarly tight to the other side (testing with the same crescent wrench on each side). I would say that this alone fixed 50-65% of my problem. I rode it tonight and it was mostly gone. I'll find a 30mm socket and check torque this week and also try the loctite and hopefully find the solution.

Doing this, and seeing no apparent damage in the inside of the head tube, makes me think that the crack is probably only gelcoat, but I'm going to watch it.

Seth

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[sethschmautz]

Quick update. I did two additional things and I think I'm creak free. I didn't have a 30mm socket so I borrowed one at work with a real nice dial torque wrench. I found that both sides were still a little loose. I think this solved 80%+ of the issue.

I then also did the inverted loctite 290 application at the stanchions and the steerer tube interfaces. On my mellow ride today I heard no creaks. I'm hoping that it at least keeps it at a low level.

Seth

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