Loud Clicking Noise

[steve52]

my clicking turned out to be the chainring bolts to tightend properly

 

[lpretro1]

Whilst it sounds unlikely, it can also be the stem bolts have got a bit of dirt or are dry or both! Take them out, clean and grease threads before replacing at the correct torque.
Also check that it isn't yuor heel catching on the front derailleur cable end cap as you pedal

 

[Katiesbloke]

I've got exactly the same gear problem on my Giant Defy 2. After several gear adjustments by the shop, I took it back again and they decided the standard chain was too wide so they fitted a thinner Shimano chain. After a few rides back came the clicking sound, then it started slipping out of gear, and then it snapped! Back to the shop, they fitted a new chain (another thin chain same type)...and the clicking sound has returned and bike wants to slip out of gear. No amount of gear adjusting makes any difference - so it's back to the shop again! Starting to think it's a design fault???

 

[goo_mason]

My SCR2 (which became a Defy when the frame was replaced last year under warranty after it cracked) started making the most horrendous creaking and cracking noise a few months later. After looking at & eliminating the old issues of the creaky seatpost and the creaky saddle rails, it came down to the bottom bracket which turned out to be so loose that I could undo the cups with my fingers....

Halfords (bike was sourced by them under Bike2Work 4 years ago) reassembled the bike after getting the new frame from Giant. 'Nuff said!