Hammertoe

Riding down a hill, I found myself in a pothole about a foot a half wide running down the road...

The top two layers of pavement were missing...

At the end I was either going to hit a large ridge or bunny hop...

Well I hopped and came down, as far as I could tell, simultaneously on both wheels and heard a loud "CRACK"...

My riding partner immediately yelled "Flat"...

Nope, tire was fine...

It was not chain slap...

No spokes broken, no cracks in the rim...

I do not think I could have cracked the Cervelo frame and there were no obvious problems...

Rode fine the remaining 45 miles...

What could it have been...

Tire bead popping, seatpost ( but I believe I was out of the saddle)...

Any ideas, areas I should check...

JoelS

Are you sure it wasn't chain slap? I get that just about every time I end up hopping something.

Hammertoe

No, I do not think so, it was too short and loud, like a tire popping...

I have a padded chainstay protector as well...

Maybe headset but it too is tight and seemed fine...

DScott

Skewers?

Some, especially the lightweight alloy/Ti ones (like KCNC) just don't grab tight enough to prevent that sound. It's more than a little disconcerting...

Hammertoe

^^^Hmmmm...

wcoastbikr

Check the hubs for cracks?

FightingPanther

look over your headset real good

DScott

To elaborate- I just "upgraded" the 117gm Record skewers I was using to these 45gm bad boys from KCNC:



Ever since, I get that "crack" sound hitting the lips of things. Not something you want to worry about when you do a lot of climbing (and descending). I'm OK with it now that I realized it's not signalling the imminent failure of the steering tube, handlebars or stem. Or, so I'm hoping...

My theory is that the Ti skewer and/or the alloy locking bits flex then grab and "pop" just a bit under extreme and sudden load. I'd guess something similar for you, especially if you have carbon dropouts on your fork like I do.

Still, check your fork, handlebars and stem.

Hammertoe

Yes, carbon drop outs...Could be...

I will take apart the headset before I ride that bike again and take a look at the steerer tube...

skiph

Check to see if the handlebars have rotated slightly (probably down) in the stem.

I had similar "CRACK"-ing sounds happen to me after hitting a pothole (twice) before finally noticing my handlebars had rotated down. Looked the whole bike over for damage...didn't find any.

Then it happened again after a teardown/rebuild...handlebar clamp not tight enough.

Then, just a few weeks ago, after bunny-hopping a pavement break while going down hill about 25 mph. This time a new stem had been put on not too long ago. Clamp bolts not quite tight enough again.

It's easy to fix now, as I have a mark on the bars to line up with the main part of the stem so I can tell if it has moved.

Both times I had my hands on the hoods, so was putting down-pressure on the bars when I landed or hit a hole.

By now, I recognize the sound, and don't freak out thinking the CF frame was 'exploding'.

petebow

yeah i was going to say handlebars in the stem. that happened to me last weekend even tho i have the bolts torqued to the recommended amount.

wcoastbikr

The stem has happened to me as well...except it wasn't a cracking noise...it was more of a tinging noise whenever I put pressure on the bars. For example like climbing out of saddle or in a sprint. Not a pleasant sound when you're out of saddle climbing up a narrow road hoping something doesn't snap.

You might want to remove it and clean the headtube and around where the bearings sit. I've found dirt and grime get in there over time and can make a little noise as well.

Hammertoe

I did notice the hoods seemed rotated further down during the ride...

But I had not ridden the Cervelo in some time and thought it was just the overall lower handlebar position...

I will take a look at this as well...

Thanks...

Grumpy McTrumpy

using carbon assembly compound?

evenslower

Shimano brifters?, did you land hard enough to make the brake levers move and "slap" back into position? I've experienced the same unnerving sound bunny hopping a speed bump. Fiddling with the levers to replicate the sound put my mind at ease. I thought I broke my fork.

big john

I've had that, but you can tell it's up high.
The last big crack sound I had was a bottle cage breaking when slamming a pothole. The riders around me all thought something major had broken and moved away. The bottle just broke through the bottom of the cage with a loud snap.

Brian Ratliff

handlebars.

ericm979

I've heard that sound when hitting rough pavement on my Cervelo R3. It's not the bars moving in the clamp (use a marker to draw a line on the clamp and bar so you can see if the bars rotate in the clamp) or the brake lever "clack" or the wheel moing in the dropouts. It's not the steerer tube- it's happened with two different forks, neither of which have broken (first one replaced due to Cervelo recall).

I think it's chain slap. Yes, even with the foam pad on the stay. Something about the frame design makes that noise really reverberate. It sounds like something expensive just broke. We have a lot of rough roads here so I have been hearing that noise regularly since I bought the bike three years ago. My other road bike makes a typical chain slap noise on the same bumps.

Metzinger

Your wicked hopping skillz obviously cracked the space-time continuum.
Nobody is supposed to be that awesome at this point in history.
Now you've f***ed it up for all of us.

Thanks a lot.

kudude

do you have a frame pump?

bikerist

Hello sir! Is that normal? When I try to make the front wheel hop, just little bit of hop or pass through an uneven surface, it makes a noise on the fork or skewers. Is that okay?

Fox Farm

Check your seat clamp.

bikerist

It was the handlebars. The screws on the stem were not tight enough. Everytime I tested it with a mini jump, the bars would rotate and thus making the sound. Checked the skewers, they appear fine for now,

Fox Farm

it could also have been your headset bearings so you might want to remove them and inspect and reinstall.