roadmax

Noticing the stock front brake rotors have aluminium hubs but rears are steel that is prone to rusting.
Are there any other newer BMW rear brake rotors with aluminium hubs that are exact fit for E60 550i ?

audiophool

Not aluminium, rather they're plated with a corrosion inhibitor. Your rears must be a lower grade replacement used at some point in the service history. I used Zimmerman on my 535xi. Rock Auto shows a number of rotors that have the plating.

roadmax

Just found in parts system p/n 34216763827 shows in picture it does have aluminium hub:
https://www.realoem.com/bmw/enUS/sho...diagId=34_1327

audiophool

Ah, LW rotors. But still, on those that are fully steel, like the rears you're complaining are rusting, can be remedied using the plated rotors mentioned previously.

PS: I'm quite surprised somebody from the US calls it aluminium. Most call it aluminum, whatever that is.

roadmax

Plenty more miles left before next brake rotor replacement so until then this is the solution for me, painted rears with high temp caliper paint, see pictures during and few weeks after (sorry for dirty wheel appearance).

w84me

how are those zimmerman's holding up for you?

audiophool

Just fine - not a spot of visible rust.

w84me

good to know. I'm probably getting close to needing new rotors and was tossing the idea of drilled/slotted. not sure if they are worth the extra cash ......

audiophool

Drilled/slotted? They're pretty but drilling holes reduces thermal mass from the rotor. No need on a street car. Zimmies have treated me well.

FormerE30Owner

I vote for Zimmerman also. Get drilled/slotted only for cosmetics, as there really is minimal performance advantage and actually some disadvantages on a streetcar.And they will will produce more brake dust too!