[dinan5m3]

WTF........................... wholly crap batman !!!



Is this it ?

Also i am certain pre-lci is one piece (both front and rear), from look of it at least i don't see how the g01 wheels can be two pieces, unless there is way to remove the center section that is super secret.

[mattsheng]

Originally Posted by dinan5m3

Do the lci have same rotor specs as pre-lci? Do you know?

All G01/G02 M40i share the same brake rotors part number regardless of the model year, so yea they have the same spec.

[Rottweiler]

Originally Posted by dinan5m3

WTF........................... wholly crap batman !!!



Is this it ? I am certain pre-lci is one piece, from look of it at least i don't see how the g01 wheels can be two pieces.

Those didn’t show as compatible with my 2023 per the vendors I checked with though the specs seem to align

Now I’m even more confused

[dinan5m3]

Dude, double, tripple check your rotor part numbers !!!

Are they these part numbers ???!!!!!!!!!!!!!!!!!!!!!!!!!! (or newer that are same just superceded these ?)

34-11-6-860-911
34-11-6-860-912
34-21-6-860-925

If so, then we just cracked the secret code !!!

[mattsheng]

Originally Posted by dinan5m3

WTF........................... wholly crap batman !!!



Is this it ?

Also i am certain pre-lci is one piece (both front and rear), from look of it at least i don't see how the g01 wheels can be two pieces, unless there is way to remove the center section that is super secret.

Zimmerman isn't an OE supplier for G01 rotors. But the OE rotors are clearly 2-piece: https://www.ecstuning.com/b-genuine-...t/34116860911/

Maybe pre-LCI cars had an older revision of the rotors.

[dinan5m3]

Originally Posted by mattsheng

Zimmerman isn't an OE supplier for G01 rotors. But the OE rotors are clearly 2-piece: https://www.ecstuning.com/b-genuine-...t/34116860911/

Maybe pre-LCI cars had an older revision of the rotors.

I've seen that picture. How do you see that center section ever coming off? Is the center section aluminum?

[Rottweiler]

Originally Posted by mattsheng

Zimmerman isn't an OE supplier for G01 rotors. But the OE rotors are clearly 2-piece: https://www.ecstuning.com/b-genuine-...t/34116860911/

Maybe pre-LCI cars had an older revision of the rotors

A thousand apologies if this has been answered already, but if the specs are all the same (fit), then why are/are not one piece and two piece rotors interchangeable/not interchangeable?

Disregard any weight differences

[mattsheng]

Originally Posted by dinan5m3

I've seen that picture. How do you see that center section ever coming off? Is the center section aluminum?

If it is a 1-piece rotor, there won't be any rivets, would it? Also, the ATE catalog says it is a 2-piece rotor: https://web.tecalliance.net/ate/en/p...eNumber:146539

I bet the center section is some sort of alloy because why else would BMW make it a 2-piece rotor?

[dinan5m3]

Originally Posted by mattsheng

If it is a 1-piece rotor, there won't be any rivets, would it? Also, the ATE catalog says it is a 2-piece rotor: https://web.tecalliance.net/ate/en/p...eNumber:146539

I bet the center section is some sort of alloy because why else would BMW make it a 2-piece rotor?

So this is a fake two piece not the usual two pieces that allow one to change the disc without the center. But then again, BMW wouldn't have thought that through for the owner any how.

As for center section you are just guessing, but i'll give you the benefit of doubt i suppose.

[dinan5m3]

Originally Posted by Rottweiler

A thousand apologies if this has been answered already, but if the specs are all the same (fit), then why are/are not one piece and two piece rotors interchangeable/not interchangeable?

Disregard any weight differences

There isn't, on ~4,000 lbs suv. Unless the stupid sw/hw on the car is stupid sensitive to that difference.


Or is there?

[mattsheng]

Originally Posted by Rottweiler

A thousand apologies if this has been answered already, but if the specs are all the same (fit), then why are/are not one piece and two piece rotors interchangeable/not interchangeable?

Disregard any weight differences

They should be interchangeable. Even Zimmerman's catalog cross-reference the 2-piece LCI rotors (34116860911):

https://web.tecalliance.net/otto-zim...eNumber:132498

[mattsheng]

Originally Posted by dinan5m3

As for center section you are just guessing, but i'll give you the benefit of doubt i suppose.

If it is not some sort of alloy, then the hub should have some coating like the Zimmermann one-piece rotor, or else it will just rust.

[dinan5m3]

Originally Posted by mattsheng

If it is not some sort of alloy, then the hub should have some coating like the Zimmermann one-piece rotor, or else it will just rust.

My *guess* is zinc plating (and i have those on my stoptech, and still can rust)

[g11hoonigan]

Originally Posted by dinan5m3

So this is a fake two piece not the usual two pieces that allow one to change the disc without the center. But then again, BMW wouldn't have thought that through for the owner any how.

As for center section you are just guessing, but i'll give you the benefit of doubt i suppose.

Those riveted 2-piece is still real but focused just to save weight (hat is lightweight). But they don't give the benefit of rebuilding and replacing just rotor in case it has worn out overtime. The 'rebuildable' 2-piece would be even more expensive.

I don't see any issue if it's one-piece. I'd worry about the weight of the wheels/tires more than rotor. The closer the weight to the center is, the less is its effect on performance than the one that extends farther from the center like wheels/tires.

[dinan5m3]

Originally Posted by g11hoonigan

Those riveted 2-piece is still real but focused just to save weight (hat is lightweight). But they don't give the benefit of rebuilding and replacing just rotor in case it has worn out overtime. The 'rebuildable' 2-piece would be even more expensive.

In that case i'm even more confused as to why anyone would go out of their way to get a zimmerman 2-pcs versus OE since the prices (with shipping) are about the same, if not little cheaper with OE. *Maybe* zimmerman 2-pcs are *better*, dunno for sure.

Nonetheless i guess i'll find out soon enough.

[bpcg928]

Can someone confirm from the info in this thread that the caliper is NOT the same between stock M340i sport brakes (348) and the rotor that is used for the ZTK option?

If it IS the same, the actual reason brakes work is anulus numbers (a factor of two radii) and the size of the caliper for general head dissipation. A larger rotor is heavier, and will make sometimes sizable differences in feel due to unsprung weight increases.

[Rottweiler]

Originally Posted by bpcg928

Can someone confirm from the info in this thread that the caliper is NOT the same between stock M340i sport brakes (348) and the rotor that is used for the ZTK option?

If it IS the same, the actual reason brakes work is anulus numbers (a factor of two radii) and the size of the caliper for general head dissipation. A larger rotor is heavier, and will make sometimes sizable differences in feel due to unsprung weight increases.

https://x3.xbimmers.com/forums/showthread.php?t=1828020

Lots of good information in the above thread

[Ayyleoo]

Originally Posted by bpcg928

Can someone confirm from the info in this thread that the caliper is NOT the same between stock M340i sport brakes (348) and the rotor that is used for the ZTK option?

If it IS the same, the actual reason brakes work is anulus numbers (a factor of two radii) and the size of the caliper for general head dissipation. A larger rotor is heavier, and will make sometimes sizable differences in feel due to unsprung weight increases.

It seems there is a lot of confusion here. By 2 piece they mean the disc portion is one metal and the hat/hub section is an alloy stamped with the disk for quicker heat dissipation. The other 2 piece type are the carbon ceramic disk where the disk is separate. Those are Uber expensive.

[abbike18]

Originally Posted by Ayyleoo

It seems there is a lot of confusion here. By 2 piece they mean the disc portion is one metal and the hat/hub section is an alloy stamped with the disk for quicker heat dissipation. The other 2 piece type are the carbon ceramic disk where the disk is separate. Those are Uber expensive.

Second this. The stock rotors are an aluminum hat which is permanently riveted to a cast rotor. Even full M rotors are made this way (slightly different design). For the G01 you can get OEM rotors like this, or the Zimmerman's (but note that Zimmer make three versions - two piece, full steel and full steel with drilled holes).

This is in complete contrast to the two piece rotors where the rotor is actually floating on the hat to allow for massive thermal expansion, and typically separately replaceable from the center hat. I haven't seen these available in the aftermarket for our cars (but haven't really looked!)

[jrveron]

Originally Posted by abbike18

Second this. The stock rotors are an aluminum hat which is permanently riveted to a cast rotor. Even full M rotors are made this way (slightly different design). For the G01 you can get OEM rotors like this, or the Zimmerman's (but note that Zimmer make three versions - two piece, full steel and full steel with drilled holes).

This is in complete contrast to the two piece rotors where the rotor is actually floating on the hat to allow for massive thermal expansion, and typically separately replaceable from the center hat. I haven't seen these available in the aftermarket for our cars (but haven't really looked!)

Paragon makes truly 2-piece rotors for the X3, front & back: https://paragonbrakes.com/bmw/5-series/5-series-gxx/

Some users here in the forum have already installed them.