Username, was going to suggest pad movement also. I have similar noise when braking but only after everything heats up. Suspect increasing clearances between pads and caliper with increasing temperature, hard to test as once cooled down the noise disappears. Intend packing the pads in the calipers to reduce cold clearance and see if it has any effect.

The click is there from the start. Could be the mudguard bracket because it's a crappy one from ebay and it's not properly fixed to the fork. I'll remove the mudguard to test it but the click I can feel through the handlebars and it seams unlikely that a light and soft plastic part could cause that effect. I have no stand to test the headraces, will ask for someone to lean on the bike while on the sidestand to unload the front. Also I tried to order original mudguard brackets from japan but they were out of stock does anyone know where can I get those?

i had the problem with clicking calipers, turned out the numpty who i bought the bike off had forgotten to put the pad springs back in, causing the pads to rattle around when i was on the brakes. Was so annoying trying to figure out what was causing the noise. but if you have replaced the calipers and everything i doubt its that, still worth a look though.

It was the headrace bearings. Damn those speed bumps.