Scooterotica

Been using a dirty sanchez (mmw/lth) front disc brake for about 500 miles and it's been brilliant. Problem now is the brake Judders like hell when I brake, as if it's grabbing on and off. Everything on the front end is as it should be with no play in bearings and links etc. Pads are hardly worn, disc not worn and runs true. There does seem to be some slight marks running (radially?) from the centre of the disc outwards.
Caliper is an srt/6 type 4 pot.
Anyone had any similar problems? Are the pads used in this Caliper an issue, or would bleeding the brake help?
Thanks.

Probably off the mark here, but I had similar problems when I first got me GP on the road, everything at the front end was checked and was found to be fine, then me mate noticed me headset bottom was ever so slightly catching on me horncase, a bit of fettling and it was right as rain. May not be the cause of your troubles but a simple check won't hurt.

Must admit my first thoughts were either a warped disc or loose/worn steering bearings........

If its anti dive check the steering bearings, the top ones take a lot of force, I've found its best to use lose balls, just get another bearing remove the balls from both of the cages and fit as many as you can.

Thanks for the replies, seems to be ok now. Took it all apart and the pads seemed to be ok, but a bit glazed over and a couple of light scores. Sanded them on a flat surface and gave the disc a light clean with wet and dry. Did about 60 miles and it's all good. Changed the brake fluid as well as it looked a bit murky.
Took the tip about using loose balls top and bottom already re the anti dive, thanks.
Can only think that something maybe got into contact with the pads or disc and didn't go down too well, or the pad compound isn't the same all the way through.
When the brake was juddering, it felt like the whole front end was going to fall off.
Thanks again for the help.