Front Brake disc groove query

[Retap]

Hi all its been a while

Just changed front pads and discs on Nigel it was overdue and has resulted in restoration of great braking performance.

The only oddidty i keep puzzling over is this edge groove machined out on one of the Eicher discs, only on one disc though not both??? see photo below. The discs that came off did not have this any ether....

At first I worried this loss of material from the edge of the disc may cause inbalance but its closer to axle centre so maybe not to bad still a slight inbalance but still puzzling what it is. My only real rational is a wear marker but why not machine this on both discs then or evenly around the circumference to keep it balaned? Could this groove actuaally be the factory balancing process of the disc? Do we think this is a flaw or seconds reworked part?

Hmmm, any thoughts?

[Popcorn]

Never seen that before, I would guess at it being for balance but wow that disc was way out if that's what it's for
Just done a little search on Google apparently it's a disc wear indicator
https://www.pistonheads.com/gassing/...&t=720952&i=20
Just scroll down and all is revealed.

[Retap]

The old discs where well ready i reckon a good 1/8" was gone they where mentioned in last mot so planned to do them at this time but the wear on th eold discs was not far off these grooves in the new disc but i to have not seen it before and found it odd especially as just seems to be machined out on one of the discs and not both of them.


EDIT


Strange the disc wear indicator is only machined on one disc i will have to recheck that next time the wheels come off.

[maxi_crawf]

I've always assumed it was to balance the disc, I have a set of new rears to fit on my 190 and one of them has the same bit (more or less) machined out of the edge.

[daveo138]

Hard to tell from the photo, but it doesn't look like a machined finish.

[Popcorn]

Looks like proper rough ar$€d grinding,if my surface finish was like that I'd get the sack you can see where the wheel has bounced

[Ducati750cc]

Originally Posted by Retap

Hi all its been a while

Just changed front pads and discs on Nigel it was overdue and has resulted in restoration of great braking performance.

The only oddidty i keep puzzling over is this edge groove machined out on one of the Eicher discs, only on one disc though not both??? see photo below. The discs that came off did not have this any ether....

At first I worried this loss of material from the edge of the disc may cause inbalance but its closer to axle centre so maybe not to bad still a slight inbalance but still puzzling what it is. My only real rational is a wear marker but why not machine this on both discs then or evenly around the circumference to keep it balaned? Could this groove actuaally be the factory balancing process of the disc? Do we think this is a flaw or seconds reworked part?

Hmmm, any thoughts?

It's for balancing ����


https://www.youtube.com/watch?v=p8mfw3WYBAM


And how it's done.


https://www.youtube.com/watch?v=SS12QOByiN8