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Loud pop in headset when hitting big potholes, any ideas?(22 posts)

Loud pop in headset when hitting big potholes, any ideas?regbike
Jun 24, 2002 8:01 AM
I just purchased an orbea force carbon, with a reynolds ouzo pro carbon fork and a cane creek integrated headset. There is no play in the headset, but whenever I hit a large pothole or substantial dip, I hear a loud crack or pop in the headset area. Any thoughts? Over all other terrain, bumps, cracks, etc., it rides smooth with no strange noise. It is tough to reproduce the sound without finding the right pothole at enough speed. Only happened once in 150 miles last week.

Thanks for any thoughts or help,
Richard
suggestionmr_spin
Jun 24, 2002 8:09 AM
Try to AVOID the potholes!

How do you know it's the headset? It could be the stem or the bars. I'd say it is more likely one of those rather than the headset.
suggestionregbike
Jun 24, 2002 8:57 AM
Believe me, I try to avoid the potholes at all reasonable costs. I am not totally sure it is the headset, but it is in the headset, steerer tube area. This fork has a carbon steerer tube. It sounds like something is going to crack.

Thanks for the input.

Richard
happends to meishmael
Jun 24, 2002 8:11 AM
It happend on my oclv with a aluminum steerer and my newer rhenolds carbon steerer. I thought it was the kyseriums. It sounds like a blow-out to me. It only happends when I hit something big, its very rare, only happend about 6 times in 2 years. Im still here and nothing has broken thats all I can say. Do you have Kyseriums?
happends to me too....bob_vanderhaus
Jun 24, 2002 8:29 AM
I have a giant tcr and have heard this about 5 times as well. It is a horrible sound, but I have not broken anything yet. I thought it was the ksyriums at first as well, but talking to other people on my team, it seems to be a fairly common at least on our giant tcr team bikes no matter the wheelset.
Using Bontrager wheels, carbon steerer tube, ITM Stem, CC Aheadsregbike
Jun 24, 2002 9:00 AM
Yeah, I'm just worried something is going to break and then I'm going to come down crashing. I am going to pull out the fork and looks for cracks, etc.

Richard
re: Loud pop in headset when hitting big potholes, any ideas?rwbadley
Jun 24, 2002 8:44 AM
When I switched from a steel fork to the carbon fork, I experienced the same popping sound. Scared me at first, looked for cracks, could find none.

I can only guess it is related to the fork, hopefully it will not cause harm.
Loud popLeroy
Jun 24, 2002 9:27 AM
This exact thing happened to me on my last ride, Tour of Italy [Texas] and it was the handlebars twisting. I hit a pothole going about 20mph. I was on the hoods and the bars popped loudly and they visibly twisted forward a bit. There are probably other explanations, but in my case the carbon steerer was fine.

Dave Loving
How do you like your Orbea?? nmJBurton
Jun 24, 2002 9:36 AM
So far I really like it.regbike
Jun 24, 2002 12:19 PM
I am still getting used to it though. It took about 2 weeks to get everything adjusted to where I like it. It is stiff but not punishing, I've ridden at least 250 miles. I have the carbon rear seat stays and they work really well do dampen things down. It is definitely not like the other aluminum bikes I've ridden which were harsh. The only complaint so far is the popping sound. Quick, responsive, smooth, lightweight, and beautiful color scheme.

Richard
The Answer!?grzy
Jun 24, 2002 10:54 AM
I've heard/felt it on several occassions, but have come up with an explanation and have witnessed it with Shimano equipment. The answer is that it's one or both of your brake levers. The sudden jolt of the pot hole accelerates the bike in the vertical direction and the STI levers, being heavy, lag the upward displacement (conservation of momentum, etc.) and when they catch up they snap home against their stops making the loud popping noise.

Not that you want to go wacking large potholes, but if you keep your hands on the hoods you can feel it happen.
um...lonefrontranger
Jun 24, 2002 11:03 AM
grzy that's a really cool analysis, but it happens on my Campy bikes as well.

I've heard this scary noise(fortunately rarely) on both of my Record equipped bikes. Both are Al frames, both carbon steer tube straight blade forks, both still intact. It happens whether I'm running the Zipp 303s or the Mavic Cosmos. There's a goodly sized lateral seam (young speed bump) in the road on a local canyon descent (Lefthand Canyon) which will produce the noise if I don't unweight before hitting it.

It must have something to do with the CF steer tube? Hopefully not terminal, cause damn it is a bad noise!
Ain't the CF steerer.Sintesi
Jun 24, 2002 12:27 PM
I get this noise on my steel forked bike.
The problem with being PCgrzy
Jun 24, 2002 5:08 PM
Actually the phenomenon can happen on either Campy or Shimano bikes. I qualified my comments to Shimano b/c that's what I ride and know.

Think about it this way how many times can a CF steerer (or any other material) make a large noise like it's going to fail, yet keep going? Maybe once or twice - then you're in the ditch. the fact that no one has found anything means you at least owe it to yourself to open you mind and check it out. Something is being accelerated on the bike at different rates and when it catches up you get the "wack".

The size and and abruptness (rate of change in acceleration = "jerk", by def.) has everything to do with how hard you wack the potholes and weahter you're weighted on the bike or not. Since youv'e got a regular ride on which you expereince the problem it should be quite easy to check it out. Just be careful wacking bumps at speed while riding the hoods - it's a really good way to make the bars move in the stem and experience potential loss of control. The alternative is to ride deep in the drops with your hands slightly compressing the levers, but not braking - this way they can't slam against the stops. Either that or buy new forks and send the "cracked" ones to me ;-)
loose headset?DougSloan
Jun 24, 2002 1:14 PM
I see you said "no play" in the headset, but maybe there is a tiny bit, and the pothole first unloads then smacks the races and bearing together. I've had this happen on several bikes with various drivetrain, forks, headsets, and frames.

If it's anything but that it's sort of scary to think about.

Has anyone tried to duplicate the noise in a controlled test?

Doug
loose headset? seems likelygoathead1
Jun 24, 2002 3:59 PM
I've had this happen on a ti bike with a CF fork with steel steerer tube. Shortly after it happened I noticed that the headset was indexed (pitted races). That seems like it would support Doug's theory. I know a couple others who have experience the same noise, and it seems like it only occurs with threadless headsets.
loose headset? seems likelygrzy
Jun 24, 2002 5:13 PM
Headset is very easy to determine and various people are reporting the problem with threaded steel steerers as well - so this eliminates the HS. What you need is a nice tight bike and a quick fork (i.e. fast frequency response) to get the effect.

I played around with it and finally figured, in my case at least, that it's the brake levers slamming back against the stops and I was able to prove it to myself and actually observe them moving. The funny thing is no one has suggested anything similar - I'm either insightful or way out in left field. Possibly both.
i too found a solutionishmael
Jun 24, 2002 5:41 PM
Ive done some experimenting and have found that, in my case atleast, if while going over the bump I firmly hold my lower jaw in contact with my upper the sound disapears.
LOL!grzy
Jun 24, 2002 6:03 PM
Me? I just avoid the big potholes - yeah I know it sounds crazy....
re: Loud pop in headset when hitting big potholes, any ideas?roadmeister
Jun 24, 2002 5:40 PM
I too have had this happen on a new C-40 W/Star fork...
it happened a few times on the first 10-15 rides, but has since only happened once or twice. It sounds as though the star nut inside the carbon steer tube is moving slightly (seating itself?).I can find no play in the headset assembly, but am going to tighten the cap (VERY slightly) to see if this works.
AHHHH!!! you have a star nut in a carbon steerer tube?!!!ishmael
Jun 24, 2002 5:47 PM
bad news. some knucklehead did the same thing to mine, I had it cut out with a dremil. Seating itself? Probably more like cutting a slice through untill it finally snaps. Some mechanics say its not that bad, some say its death waiting to happend.
well, it's happened to me...weiwentg
Jun 24, 2002 7:19 PM
CF steerer, Cane Creek zero-stack headset. has happened several times, and both fork and headset are still in operation.