Front Brake Judder

[Humbug]

Having an issue with the front brakes on the 12S with a bit of judder under braking. Thought it was the age old problem of the wheel bearings but these seemed fine on checking. Had the pistons eased as they were sticking a bit but this has not seemed to provide a cure. Changed the discs and pads but still the same. One of the discs does not seem to be contacting the pads fully as there is a bit of rust on the outer edge and when I changed the pads, the pistons seem to be sticking a bit again. Ideas? Should I consider a replacement caliper?

[Justcruising]

I would first try cleaning your calipers & inspecting the pistons while exercising their operation in situ as per this YouTube example https://youtu.be/0sHQfnbf9t4 . I service mine this way incl. fluid change every 2y & they work GREAT. Good luck!

[dave the german]

Having an issue with the front brakes on the 12S with a bit of judder under braking. Thought it was the age old problem of the wheel bearings but these seemed fine on checking. Had the pistons eased as they were sticking a bit but this has not seemed to provide a cure. Changed the discs and pads but still the same. One of the discs does not seem to be contacting the pads fully as there is a bit of rust on the outer edge and when I changed the pads, the pistons seem to be sticking a bit again. Ideas? Should I consider a replacement caliper?

You could get Powerhouse automotive to do a re curb. Heard good reports. Might be dearer than a used calliper but they will be as good as new

[GerryB]

I had the same ....

EBC brake pads !!!

Waste of money , now trying Ferrodo , see how they go .

[Humbug]

Thanks for the ideas chaps
I'm wondering if I might be looking in the wrong places and should I consider the upper and lower ball joints? Anyone had experience of changing these? Cost and difficulty?

[dave the german]

Thanks for the ideas chaps
I'm wondering if I might be looking in the wrong places and should I consider the upper and lower ball joints? Anyone had experience of changing these? Cost and difficulty?

they're not that cheap - I think they're close to £100 each. have you got a manual for the bike?

[Humbug]

Thanks Dave,
Yes I have a manual but am sometimes sceptical of their idea of what is easy or difficult after removing the rear shock. My experience of removing the lower mounting bolt was a little more difficult than the book intimated involving lots of heat, damaged knuckles and a long breaker bar following the comment that the bolt is usually awkward to remove

[Humbug]

Just fitted a new set of front wheel bearings to see if this makes a difference before looking at the ball joints. That was my problem twice before so fingers crossed. I'll report back

[slparry]

I've had an out of balance wheel give the feeling of brake judder in the past, as you slow to a certain point during braking the out of balance shows up at a certain speed range …. just another thing to check

[Humbug]

Thanks Steve, I'll have a check of that if the bearings don't fix it. It seems to be at all speeds though, as soon as I apply the front brake.
Now, time to try to wrestle a new headlight bulb in when the spring retainer keeps popping out!!! What a rubbish system of a washer and screw on a plastic mount to hold the retaining spring.

[Humbug]

Well, after a new wheel, new seals and bearings and new Brembo pads, the judder remains! Discs within permissible run out, wheel straight and true. Next will need to be the callipers. Seem a bit sticky on the inside pistons and the ceramic inserts are cracked although mechanic said that cracked inserts wouldn't affect the braking.
Not sure whether to go down the Motorworks calliper repair kit, second hand callipers at £100 each with 6 months guarantee from Motorworks or rebuild of my old callipers at up to £180 each calliper.
To top it all, neutral light not indicating unless I put light pressure on the gear lever meaning bike won't start without this light pressure. Too much and 1st gear selected!!!
Another option of course to scrap the bike and get something with less miles

[dave the german]

Any play on any of the front steering/suspension bearings?

[Humbug]

nothing of note Dave, had Mike Overy have a quick look and test ride and he thought it was wheel related. I'm now hoping its a sticking calliper

[nab 301]

Well, after a new wheel, new seals and bearings and new Brembo pads, the judder remains! Discs within permissible run out, wheel straight and true.

Does the judder happen with both hot and cold brakes , and have you tried deglazing the discs? I have a Bonneville with a similar problem , the runout seems fine , I rebuilt the caliper and fitted new pads it's a lot better but currently gets worse with warm brakes . Forums suggest new discs are needed , maybe I need to check the runout with a hot disc..

[nab 301]

Well, after a new wheel, new seals and bearings and new Brembo pads, the judder remains! Discs within permissible run out, wheel straight and true.

Does the judder happen with both hot and cold brakes , and have you tried deglazing the discs? I have a Bonneville with a similar problem , the runout seems fine , I rebuilt the caliper and fitted new pads it's a lot better but currently gets worse with warm brakes . Forums suggesta new disc are needed , maybe I need to check the runout with a hot disc..