Clicking noise

I just came back from diagnosing a clicking sound on my bike. It was driving me nuts. Every time I went out of saddle and rocked the bike left and right, the damn click was there.

First I thought it was the 2-bolt stem that I had on the bike previously. I actually managed to recreate the sound when I twisted the handlebars when the bike was stationary, so I blamed it on the stem design, and even the bolts coming loose.

I put the 4-bolt stem on the bike and the sound disappeared for a while, but it returned soon. I blamed it on the stem bolts coming loose. (I have this issue with stem bolts coming loose, although torqued properly). After retightening the stem bolts, the click was still there, although now it appeared to originate from somewhere on the bottom of the bike.

Again, I tinkered with the stem, tightened the headset a bit, tightened the cranks, reinstalled the chainring and regreased chainring bolts, cleaned the chain and sprocket. I even suspected that the valve was rattling agains the valve hole when the wheel was leaning left and right. The click was still there, mostly at the bottom of the pedal stroke when out of the saddle.

So I thought I should try with the seatpost, and bingo! I removed the seatpost and tested, as usual, by riding around my yard out of the saddle with rocking the bike left and right. The click was gone.

It appears that since the seatpost was very deep in the frame, when the frame was flexing the seatpost was rubbing against the inside of the seat tube or something like that. It was a seatpost I installed recently, and it was longer than the ones I used before. I returned the old seatpost, and so far so good, or at least I hope so, since I am yet to test it on the road.