[agent_orange]

Having run hardparker's X5/X6 50i 365x36mm twin-piston front brake setup for nearly 3 years now on 2 different F25 X3s, I decided to try something a little different.

The 374x36mm and huge aluminium single piston caliper setup found on Euro F10 550i and M550d models bolts straight on with only spacers, longer bolts, and dust shield trimming.
Radial clearance is tight with the 369 19" wheels, probably about 3mm. Plenty of axial spoke clearance though.
So 19" wheels minimum and not sure if all other OEM 19" X3/X4 wheels would clear the same. 20" should all clear.

I'm running the same EBC Redstuff compound I had in the previous X5 calipers as I'm pretty happy with it, but filed off the 'brake-in' coating, so braking power was down a little initially as expected, but after ~1000km of normal town driving it is now slightly better than before and still improving.

This setup also saves 1kg per side vs the previous X5 50i, all from the calipers as the rotors are the same weight, and I actually felt the unsprung mass reduction as a very slight improvement in ride quality.
It has also given a higher brake pedal as hoped for due to less pistons. (more pistons ain't always better)

[Ol' Red Duc]

This is perfect, I saw mention of these front calipers/rotors and I'm glad you already put them to the test. These make use of hardparker's bolts/spacers, yeah?

You used which carriers? 34116786820 or 34116786829? I assume the difference in those carriers (xx29 being Euro) is what allows the use of the larger rotor in the same caliper?

[agent_orange]

I got spacers custom made locally and used longer OEM e-torx bolts meant for the front diff I think, but hardparker's rear spacer and bolt kit should work for this.

Carriers must be the Euro *829 ones to work with the 374mm rotor.
The correct 374mm *829 carriers have '929' cast into them. The 348mm *820 ones have '928' cast in.
I ended up buying some complete low-mileage calipers with the right carriers from eastern Europe on eBay after verifying the carriers in the photos.

It's quite possible that certain G series 4-piston calipers will also bolt up with the same spacers with this F10 374mm rotor or the alternative F01/Alpina 374mm rotor with smaller hat as some F10 guys have done it, but probably have to grind the inside radius of the brake pads and run wheel spacers.
I didn't want to deal with that and actually wanted a single-piston caliper.

Credit to the F10 brakes thread:
https://f10.5post.com/forums/showthr...488894&page=10

[najnad]

Tempting, but I run 18" rims in the winter. Nice work

[Rube]

Originally Posted by agent_orange

I got spacers custom made locally and used longer OEM e-torx bolts meant for the front diff I think, but hardparker's rear spacer and bolt kit should work for this.

Carriers must be the Euro *829 ones to work with the 374mm rotor.
The correct 374mm *829 carriers have '929' cast into them. The 348mm *820 ones have '928' cast in.
I ended up buying some complete low-mileage calipers with the right carriers from eastern Europe on eBay after verifying the carriers in the photos.

It's quite possible that certain G series 4-piston calipers will also bolt up with the same spacers with this F10 374mm rotor or the alternative F01/Alpina 374mm rotor with smaller hat as some F10 guys have done it, but probably have to grind the inside radius of the brake pads and run wheel spacers.
I didn't want to deal with that and actually wanted a single-piston caliper.

Credit to the F10 brakes thread:
https://f10.5post.com/forums/showthr...488894&page=10

Nice find! I think These are also the us spec F01 750i brakes. Realoem shows the same part #s for the F10 550 and F01 750 374x36mm rotors (left - 34116785675 right - 34116785676) and corresponding caliper with the carrier that has the 929 stamped on it (caliper carrier part # 34116786829)
Few questions if you don’t mind…..How much dust shield trimming was required? Were you able to reuse stock brake lines and How does the pedal feel and braking power ? My brakes are due soon and I may go with this.
Thanks

[agent_orange]

Originally Posted by Rube

Nice find! I think These are also the us spec F01 750i brakes. Realoem shows the same part #s for the F10 550 and F01 750 374x36mm rotors (left - 34116785675 right - 34116785676) and corresponding caliper with the carrier that has the 929 stamped on it (caliper carrier part # 34116786829)
Few questions if you don’t mind…..How much dust shield trimming was required? Were you able to reuse stock brake lines and How does the pedal feel and braking power ? My brakes are due soon and I may go with this.
Thanks

I think you are right with the US F01 750i having the same parts, RealOEM shows all the same part numbers including the caliper body.
I know there is a different 374x36mm setup with wider pads, a smaller rotor hat, and a caliper body with a flat edge all the way across the inside, not bevelled like the 550i calipers, but this may be an Alpina or Euro F01 setup, not sure.

Not a huge amount to trim off the dust shields, I didn't take pictures of the template and cutting unfortunately.
Actually installed new dust shields while I was doing this swap, so had to trim them again. (The ones previously trimmed for the 365mm twin piston setup would have only required a tiny extra snip at the outside corners)
Yes, stock brake lines.



Pedal feel is good but not great. Better than the previous twin piston calipers, but not as good as the stock calipers.
I'd installed a 27mm master cylinder as well when I still had the previous 365mm setup, but 2015/08 onwards builds have that as stock already.
Braking power is pretty good, better than stock and it also requires less pedal effort in normal braking than my M2C which has the same EBC Redstuff pad compound.
The braking power/pedal effort is highly pad dependent though, if you use ceramic low-dust pads in a big setup like this, it will have less braking power than the stock setup and OEM pads, particularly initial bite.
Ask me how I know this...