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Its a rear big brake kit Jim, but not as you know it!

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B21
Lifer
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Its a rear big brake kit Jim, but not as you know it!

Post by B21 » Sat Jan 11, 2025 10:32 am

RobbiZ4 wrote: Fri Jan 10, 2025 11:42 pm Great news!

Do you already have an idea, which material will be taken for the adapters? Maybe I can ask the German TUEV inspector about his view and requirements for such a solution.

Short summary:
- 345mm x 24mm (p/n 34216775289) rotors new from BMW cost about 130€ each.
- partnumbers of the rear calipers are 34216793047/34216793047? New from BMW 290€ each.
- brackets 34216793053/34216793054? New from BMW 240€ each.
Robbi..here is a DRAFT version of my buying / installation instructions…it would be helpful to have a review of this…I’ll edit it as we get closer
to production date..likely February..

https://www.dropbox.com/scl/fi/qscymxyp ... ny9m8&dl=0

The adaptor plates are oversized relative to the loads they’ll endure (they are nearly twice as thick in cross section compared to the caliper carrier..and they are in rolled steel compared to being cast like the cradle)…

There is a choice of materials that they can be made from …S355J2 cold rolled steel or 304 stainless …stainless is about 5 times more expensive..

Any thoughts on folks paying an extra £40 over the basic price for stainless..?

I’d suggest folks buy their stuff from Autodoc..

Practically buying BMW versions are unnecessarily expensive …

The calipers and discs are pretty low tech…if you’re fussy you can buy high carbon discs with / without pretty holes much cheaper elsewhere..

My doc has target pricing ..of course you can buy BMW product ..but IMHO it’s unnecessary..

I would assume even in Germany if the product is supplied by Autodoc and is for the exact BMW part number that should be OK?

I’ve bought a variety of non BMW versions of discs , calipers and cradles and can’t see any issues…

A complete solution for 345mm should be around £500-£600 and for 370mm should be around £600-£700
“We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard”….
One of 258 Atacama Yellow 35is…165 modifications and updates…and counting.. :tumbleweed:

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Its a rear big brake kit Jim, but not as you know it!

Post by RobbiZ4 » Sat Jan 11, 2025 10:52 am

B21 wrote: Sat Jan 11, 2025 10:32 am Robbi..here is a DRAFT version of my buying / installation instructions…it would be helpful to have a review of this…I’ll edit it as we get closer
to production date..likely February.
Got it, thanks.
Will have a look on it tonight.


Using original BMW parts might reduce discussion points with the TUEV inspectors.
Can you evaluate the material quality used from my material sheet I sent to you?
:ant:
Z4 E89 Roof Topics
viewtopic.php?t=130932

Y1 ... Y4 Roof Diagnostic Systems for BMW, AUDI, VOLVO
viewtopic.php?f=23&t=129048
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B21
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Its a rear big brake kit Jim, but not as you know it!

Post by B21 » Sat Jan 11, 2025 11:12 am

RobbiZ4 wrote: Sat Jan 11, 2025 10:52 am
B21 wrote: Sat Jan 11, 2025 10:32 am Robbi..here is a DRAFT version of my buying / installation instructions…it would be helpful to have a review of this…I’ll edit it as we get closer
to production date..likely February.
Got it, thanks. :thumbsup:
Will have a look on it tonight.


Using original BMW parts might reduce discussion points with the TUEV inspectors.
Can you evaluate the material quality used from my material sheet I sent to you?
The steel used in that bracket / data sheet is super high quality stuff normally used for con rods and pistons pins.. :thumbsup: :thumbsup:

Not sure it’s actually relevant in this case as the bracket in ‘normal’ low carbon steel is ..the ultimate strength is about 50% of that steel..

I’m not aware of the argument of say a BMW supplied disc vs say a Brembo that Brembo says fits.. :tumbleweed:
“We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard”….
One of 258 Atacama Yellow 35is…165 modifications and updates…and counting.. :tumbleweed:

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Its a rear big brake kit Jim, but not as you know it!

Post by RobbiZ4 » Sat Jan 11, 2025 11:15 am

Well, BREMBO is OEM, i.e. Zimmermann AFAIK not. For the latter a special document is required (i.e.ABE).
Last edited by RobbiZ4 on Sat Jan 11, 2025 11:25 am, edited 1 time in total.
:ant:
Z4 E89 Roof Topics
viewtopic.php?t=130932

Y1 ... Y4 Roof Diagnostic Systems for BMW, AUDI, VOLVO
viewtopic.php?f=23&t=129048
Image

User avatar
B21
Lifer
Lifer
Posts: 6984
Joined: Tue Oct 05, 2021 7:15 pm
Location: In my Banana Yellow Space Shuttle...somewhere over Southern Caledonia

Its a rear big brake kit Jim, but not as you know it!

Post by B21 » Sat Jan 11, 2025 11:22 am

RobbiZ4 wrote: Sat Jan 11, 2025 11:15 am Well, BREMBO is OEM, i.e. Zimmermann AFAIK not. For the latter a special document ist required (i.e.ABE).
Well I guess then if you buy the OE supplier versions then you’re OK..your choice ..no restrictions on my part..

FWIW that steel although strong is best suited for higher temperature applications such as those in an engine ..it’s not designed to handle cold weather issues such as found on calliper brackets on a freezing day..
“We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard”….
One of 258 Atacama Yellow 35is…165 modifications and updates…and counting.. :tumbleweed:

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B21
Lifer
Lifer
Posts: 6984
Joined: Tue Oct 05, 2021 7:15 pm
Location: In my Banana Yellow Space Shuttle...somewhere over Southern Caledonia

Its a rear big brake kit Jim, but not as you know it!

Post by B21 » Mon Jan 20, 2025 6:34 pm

Brackets for the 345mm E89 rear BBK arrived from the shop..
Attachments
IMG_3248.jpeg
IMG_3248.jpeg (150.74 KiB) Viewed 279 times
“We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard”….
One of 258 Atacama Yellow 35is…165 modifications and updates…and counting.. :tumbleweed:

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