front brake discs

[steve1964]

Hi All

I have some play in the front brake discs on my 955 rs the play is between the disc and the carrier if the bike is rocked back and forth with the brake on you can hear a knocking sound from the disc any ideas can this play be taken out

Steve

[roadduster2]

steve1964 -

This is an IMO answer. The front discs are floating type, meaning they are supposed to give a little, or as you say, 'have play in them'. If you look at them they are attached to the rigid center mount by 'bobbins'. The fact you hear a 'knock' may be caused by them giving or floating on their 'bobbins' as you rock your bike back and forth.
This is a good thing as it tells you they are free and not bound up by anything causing them to bind up. Which can happen and when it does, it causes bad front brake action. Make sure your discs are freed up and do float, which as I say, IMO they working correctly. Your brakes are working as it was meant to by the designers.

roadduster2

[steve1964]

I understand that there should be a certain amount of float but 4 to 5 mm back and forth the MOT inspector over here will wet himself when he sees that much play does any one know what the tollerance should be

[roadduster2]

steve1964

OK. 4 to 5mm of play in your rotor movement is not just a little.
So, post your year model of your bike, mileage, and this problem will have to go to some members who have more knowledge of this issue.

Hope you get it sorted out soon.
roadduster2

[CharlieS]

bump bump

[oldndumb]

Hmmmm, 4 to 5 mm is grossly excessive.

I would not ride a bike in that condition.