High-pitched metallic "ping" sound -- diagnosis?
 

For the last few rides, I have noticed a random, high-pitched metallic "ping" sound coming from (I think) the front end of my bike. (2009 Specialized S-Works SL2 Roubaix w/ Ultegra 6700 groupset & Mavic Ksyrium SL wheels.) The sound is loud enough for me to hear from the saddle and it sounds a bit like balls in a bearing striking one another when the bearing has no lube in it. The sound isn't regular or cyclical (as if my wheel or crank is striking something). The pings come in irregular clusters and occasionally don't ping at all. The bike has about 2,000 miles on it.

I changed my front wheel out -- but the ping continues with either wheel.

I re-torqued my stem and bar attachment bolts. (They were already at spec.)

I checked my headset -- There's no slop and no binding.

Any ideas on where to look next?

A wheel "ping" is usually due to loose spokes. But since it's happening to two different wheels there seems to be a different reason, unless the spokes are loose on both wheels.
Is it possible that the end of the brake cable could be hitting the spokes? Or how about the computer sensor?

I'm with Al, look for something like the end of the front derailleur wire hitting the frame from time to time. That is unless you have some friends who might have put a bearing ball into your top tube.

Spokes are all tight, front and rear. All cable ends are well clear of any moving parts. The computer sensor, too.

Great checklist items, though. I hadn't thought of those.

The frame is carbon. The ol' ball-bearing-in-the-top-tube trick would most likely make a loud, continuous "clack" sound.

You say you "think" it's coming from the front; have you checked your rear wheel spokes, hub, etc, just to be sure?

Yes

Check your brifters maybe? Or do you have anything mounted in your bar ends like a mirror that might have a loose piece inside the bar?

The one time I had that type of noise, it was because the headset bearings were completely trashed, as in the ring that held them was broken in several places, and the balls were just rollin' around in there. It also explained the shuddering on descents. Replaced both rings and it went away. Very annoying to diagnose, and the shop couldn't even hear the noise when I brought it in. I finally just had them take the front end of the bike apart, where they discovered the trashed bearings.

Brifters are solid. Nothing mounted on the bar except my Garmin -- I re-torqued that mount, too.

Sounds like a problem for Click & Clack.

It sounds like your problem is with the machine that goes "ping!" The solution is to get the most expensive machine, in case the administrator comes.

This is going to sound stupid, but if it's irregular, could it be gravel or other small road debris that your front tire is kicking up and hitting your frame?

I realize that you think it's coming from the front of the bike but noises have a weird way of bouncing around. I would try a different rear wheel and see if the problem goes away. High-pitched metallic ping noises are the noises that wound-up spokes make as they relax and unwind. Prior to unwinding, they will be tight and likely still be quite tight after unwinding (they may only turn a fraction of a turn). Rear wheel spokes can ping from hitting a bump or pedaling torque both of which happen frequently on a ride.

Yes, but only if he can accurately replicate the sound.