Tal
Living Legend
Its very normal to have forward and back play...it needs it to function correctly.
Brake discs on race bikes usually have much greater play than those discs on road bikes.
There is normally a spring washer between each mounting 'rivet' which dampens the movement between the disc and the carrier, so floating discs on road bikes don't always appear to move much.
In contrast to that, race spec discs there is much more apparent freeplay. This is to allow for the differential heat expansion rates between the disc material which is different to the carrier material.
On my last bike I fitted Brembo race discs and they used to rattle about very noticably when pushing the bike around or when the bike was stationary ticking over.
It looked and sounded quite concerning but they worked fine.
There is normally a spring washer between each mounting 'rivet' which dampens the movement between the disc and the carrier, so floating discs on road bikes don't always appear to move much.
In contrast to that, race spec discs there is much more apparent freeplay. This is to allow for the differential heat expansion rates between the disc material which is different to the carrier material.
On my last bike I fitted Brembo race discs and they used to rattle about very noticably when pushing the bike around or when the bike was stationary ticking over.
It looked and sounded quite concerning but they worked fine.
STUGT3
.040 Over
- Joined
- Oct 19, 2021
- Messages
- 79
- Ride
- 2020GT3
There is play forwards & backwards & up maybe 3-5mm , spoke with dealer today they say it could be excessive but won't comment to much until they inspect it themselves. That means a four hour ride to see them & of course they don't have parts to fix if needed, they want a deposit to order parts that I might not need 
Before you ride the bike again just check to see if all the rivets are there, by slowly pushing the bike along and checking each one in turn.
Just to be sure, you could also put your fingers on each end of the rivet and give it a wiggle to see how each one feels compared to the other. This might either reassure you that everything is consistent therefore should be safe to use, or pinpoint a specific issue.
If in the unlikely event that one or more is missing or look like they are coming out don't ride the bike until they are all as they should be.
I've just checked my rear disc and there is some movement but not much.
Just to be sure, you could also put your fingers on each end of the rivet and give it a wiggle to see how each one feels compared to the other. This might either reassure you that everything is consistent therefore should be safe to use, or pinpoint a specific issue.
If in the unlikely event that one or more is missing or look like they are coming out don't ride the bike until they are all as they should be.
I've just checked my rear disc and there is some movement but not much.
Gregger
Living Legend
Could you post a video of the play you are noticing? 3 to 5 mm is a fair amount of play.
cootertwo
Living Legend
- Joined
- Mar 24, 2013
- Messages
- 2,043
- Location
- Labelle Florida USA
- Ride
- 2013, & 2 05's R3R, 2006, 2004 Harley's, 2004 Kaw
Hummm, very interesting. "Usually" the rivets & spring spacers get gooped up with brake dust etc. and require cleaning to get any play back........
