ive got a riding pal with an issue;- under braking he gets a front end judder. He's got a standard set up with the addition of an ohlins steering damper. It has only recently started. This juddering only becomes apparent when braking quite heavily from speed.
Could be a disc, but if he get brake hard and it disappears it could be sloppy head bearings or worn fork sliders.
I had a similar issue on the cbr and was convinced it was a disc. Checked and they were very slightly out of true. But the fact they float should have taken that away. As per cab, I found the head bearings were worn a bit. Replaced and completely smooth braking now. Also worth cleaning and turning the bobbins on the disc. Can give same symptoms.
I had that when I went in to corners really fast. Turned out it was my arse twitching! On a more useful note warp disks show when you travel slowly and come to a halt. under soft brakeing the bike will lurch to a halt
