Z1OwnersClub GB

Hello all, just got my ST on the road again and:

A run up to the airport and back and a horrible rattle from front left calliper ,mmmmm .
Pulled over and left calliper defo a bit more jiggle room than right , assume:
A. the rubber bush things on the bolts that hold the caliber to the mounting bracket allowing "free floating" are worn and need replacing ?
B. The disc on one side is not seating properly as previous owner had wheels powder coated and it may not be a flat mounting surface where disc bolts to hub.?
C. Disc warped ?

Only say this as it seems to quiet when turning right but rattle is loud and constant when straight or turning left.

Any previous history of similar from anyone ( Philipe ?) or ideas, suggestions, wisdom before I strip calibers and rebuild afresh ?.
I am going to take the front wheel off and attempt runout check or remove front left disc and see if it is seating properly , think previous owner removed wheel and discs and repainted another set and put them on but swapped discs.

I have reached around the tinter web and cannot find any replacement bushings for the caliper to bracket bolts.

Pigford mentioned a previous Brake rattle thread but I have searched high and low and cannot find it .

Any thoughts or suggestions welcome except the take a long walk off a short pier or don't go out in your socks when its raining variety.....

If there is powder coat on the seating areas thats the first thing i would be getting rid of. Metal to metal as there could always be fluctuations in the thickness of the powder coat.

Thanks Angus, I will have the wheel off this week and will investigate and report back!

as it's the L side, check its not something to do with the speedo drive - it is sitting correctly ie raised part of the speedo casting below and behind the raised part on the fork leg casting to prevent it rotating forward too far? Or are the drive ears on the tubular plate correctly engaged with the speedo drive ?

Vendetta761 wrote:Thanks Angus, I will have the wheel off this week and will investigate and report back!

I worked in an industrial coating/paint shop for a good few years and out of all the coating methods powder has the least consistent depth, one extra pass over an area creates significant depth fluctuations. Its a good place to start.

So front wheel off, disc rotor off and this is what lies beneath: a couple of spots bits/bleeds, maybe 1mm,1.5mm thick but obviously extra to the surface. I will get these off and also take disk to friendly engineers to check if/how it is warped but looks good on my engineers ruler and straight edge but I am no professional.

gray wrote:as it's the L side, check its not something to do with the speedo drive - it is sitting correctly ie raised part of the speedo casting below and behind the raised part on the fork leg casting to prevent it rotating forward too far? Or are the drive ears on the tubular plate correctly engaged with the speedo drive ?

Yup, checked that, all good, well greased and seating cushty but thanks anyway.

This could be the culprit but not certainly. It is more of a reason than a warped disk but better to eliminate both possibilities.