knocking noise from rear disk calliper

[dxtans]

Hello

Noticed my rear disc pads, were pretty much shot, no wear left on them, practically metal on metal !
So had a new set of pads put on. In doing this I noticed that the rear disc
had some heavy scour marks near the outer rim of the disc.

Riding the bike I do not notice anything, all seems OK.

However when I have it on the center stand with it in gear, I notice
a knocking sound coming from the rear calliper/disc brake.Could it be that when I have drive on the wheel the disk is actually wobbling and
making that sound when the rear is actually turning at high revs? I am confused.

Turning the rear wheel manually there is nothing out of the
ordinary, I cannot identify an warping of the disc at this speed.


Is it time to replace the rear disc ?

Thanks
Dxtans

 

[Pukmeister]

Are you 100% sure its the disk and not the drive shaft joints inside the swinging arm or backlash in the drive train that are causing the knock when rotating the wheel on the centrestand??

FWIW you aren't meant to run the bike in gear unloaded on the stand, they all make a knock, try using a little rear brake to take the backlash out of the equation and I wager the knocking stops - its the backlash in the driveshaft/crownwheel and pinion hammering back and forth when unloaded.

 

[Mav]

Are you 100% sure its the disk and not the drive shaft joints inside the swinging arm or backlash in the drive train that are causing the knock when rotating the wheel on the centrestand??

FWIW you aren't meant to run the bike in gear unloaded on the stand, they all make a knock, try using a little rear brake to take the backlash out of the equation and I wager the knocking stops - its the backlash in the driveshaft/crownwheel and pinion hammering back and forth when unloaded.

Wot he said

 

[dxtans]

Hello,

Did not know that, about running it in gear on centre stand, knew you could not leave idle on stand for longer than 5 mins..

Well, err thanks you guys. Spot on. It was the drive making the thump. Feel a bit stupid now, well I have learned some thing new..again .

Thanks
dxtans

 

[Mav]

Hello,

Did not know that, about running it in gear on centre stand, knew you could not leave idle on stand for longer than 5 mins..

Well, err thanks you guys. Spot on. It was the drive making the thump. Feel a bit stupid now, well I have learned some thing new..again .

Thanks
dxtans

Nothing to feel stupid about - every day is a school day