[NathObeaN]

Hi all! I currently have the 2NH BBK fitted to my M2C. It’s seen a few tracks days and I need to think about replacing the discs. That said, I now have to decided on whether I simply replace with like-for-like or switch to the Alcon BBK. Any experience comparing the two? Is the Alcon kit worth the swap or should I just stay OEM?

[Ratcher]

For what use?

The only advantages of the Alcon BBK would be running 18s and less unsprung weight.

[NathObeaN]

Street + track. Probabaly 5-10 track days a year. I love the OEM BBKs, I just wondered if the Alcon’s were any better/worse or basically the same…

[medphysdave]

I'm really curious about this myself. I've chosen to run adapters with the stock 2NH calipers with 380mm rotors and 18" wheels. Not yet installed.

From my reading you'll get easier pad swaps, cheaper pads, and ability to run 18" wheels. Whether the caliper itself is superior I do not know. Some are getting pad knock back on the 2NH. I've also experienced it on track with the 2NH. It was only once. If it were a frequent occurrence I'd be looking to make a change. The 2NH pad is quite large with a lot of surface area. I like that. I'm also adding a bit of cooling. Mainly in an attempt to keep my nice red calipers from discoloring. I haven't had any wear issues or fading with the xp12. All of this is on a track that is known to be tough on brakes, but I'm not exceeding 125mph into any brake zones. There's likely a significant usage difference for tracks where you hit 150-160 and brake down to 60-80.

[ashmostro]

Knock back on 2nh is terrible... I would do the alcons if they have anti knock back springs.

[medphysdave]

I was looking a bit further into the pad knockback. It seems to be associated with factor outside the caliper like the rotors. Are people using the 2NH caliper experience this with stock and after market rotors? Or only stock rotors? I experienced it with stock rotors.

[ashmostro]

Floating rotors do help for sure, but won't eliminate the issue. You still need AKB springs to combat the issue once you are pulling real G's.

Worn wheel bearings will exacerbate it, but even fresh bearings can deflect enough to cause knock back.

[HP Autosport]

If you are doing only 5-10 track days a year, upgrade to Girodisc two-piece and track day pads should do the trick most of the time. We have customer running stock rotors/Giro/Paragon with Ferodo DS1.11/Pagid RS29 with great results.

[NathObeaN]

Thanks all. I realised another advantage of the Alcons is the ability to change pads without removing the caliper, something I hate about the 2NH. That said, I am struggling to find street-legal pads I can use when not on track… any ideas?

[ThreeStripes]

AP/Essex kit with DS2500 and DS1.11 or 3.12 is a popular route if you’re not set on Alcon.

[smmmurf]

Originally Posted by ThreeStripes

AP/Essex kit with DS2500 and DS1.11 or 3.12 is a popular route if you’re not set on Alcon.

This would be my suggestion as well. I have the AP Pro5000R and love the brake feel and quality.

[///MPhatic]

Originally Posted by NathObeaN

Street + track. Probabaly 5-10 track days a year. I love the OEM BBKs, I just wondered if the Alcon’s were any better/worse or basically the same…

Nearly the same. It's all about the pad. Unless you have money burning a hole in your pocket...

[NathObeaN]

I must admit, after some extensive research today I am thinking about either staying stock or getting girodisc replacements. Main reason for considering the girodisc is my OEM discs have developed some nasty cracks, and they haven’t had a crazy amount of use.

[HP Autosport]

Originally Posted by ThreeStripes

AP/Essex kit with DS2500 and DS1.11 or 3.12 is a popular route if you’re not set on Alcon.

Those are the most popular street and track pads we sell. No need to bed-in after switching.

[ThreeStripes]

Originally Posted by NathObeaN

I must admit, after some extensive research today I am thinking about either staying stock or getting girodisc replacements. Main reason for considering the girodisc is my OEM discs have developed some nasty cracks, and they haven’t had a crazy amount of use.

FCP Euro gives you free refills on the OEM discs. That way the more you track the car the cheaper your discs get, which is nice.

That may only make sense for us customers.

https://www.fcpeuro.com/products/bmw...mw-34118072017

[NathObeaN]

Originally Posted by HP Autosport

Those are the most popular street and track pads we sell. No need to bed-in after switching.

I would consider them except I am from UK and the pads are not R90 approved so technically illegal to use on the road.

[NathObeaN]

Originally Posted by ThreeStripes

FCP Euro gives you free refills on the OEM discs. That way the more you track the car the cheaper your discs get, which is nice.

That may only make sense for us customers.

https://www.fcpeuro.com/products/bmw...mw-34118072017

Sure sounds good but as a UK customer probably more hassle then it’s worth. They also say if they deem the return rate to be ‘excessive’ beyond ‘reasonable lifetime’ then they won’t replace. I would imagine it wouldn’t last long before they say no.

[Ratcher]

Originally Posted by NathObeaN

I must admit, after some extensive research today I am thinking about either staying stock or getting girodisc replacements. Main reason for considering the girodisc is my OEM discs have developed some nasty cracks, and they haven’t had a crazy amount of use.

Cracks are fine and stock rotors work perfectly. Girodisc cost nearly twice as much and dont last twice as long. Have people near me using them.

Pad knock back is real but I think it's something one can live with.

Originally Posted by NathObeaN

That said, I am struggling to find street-legal pads I can use when not on track… any ideas?

Don't bother, they don't exist. Race pads aren't legal and you want them for your trackdays. Nobody ever notices it, I am taking this risk for nearly 4 years and was never ever an issue.

[HP Autosport]

Originally Posted by Ratcher

Cracks are fine and stock rotors work perfectly. Girodisc cost nearly twice as much and dont last twice as long. Have people near me using them.

Pad knock back is real but I think it's something one can live with.

Don't bother, they don't exist. Race pads aren't legal and you want them for your trackdays. Nobody ever notices it, I am taking this risk for nearly 4 years and was never ever an issue.

What pads are they using them with? No reports of premature wear from our customers running Fedrodo DS1.11 or DS3.12 pads. Can't comment on other pads and compounds.

You don't get true two-piece rotors because they last twice as long. You get them because of the less likely chance of distorting from the full floating design. You get them because of the improved vane design for better cooling. Some people get them because they look cool!

[medphysdave]

Originally Posted by HP Autosport

What pads are they using them with? No reports of premature wear from our customers running Fedrodo DS1.11 or DS3.12 pads. Can't comment on other pads and compounds.

You don't get true two-piece rotors because they last twice as long. You get them because of the less likely chance of distorting from the full floating design. You get them because of the improved vane design for better cooling. Some people get them because they look cool!

Seems like this would be one step towards helping with knockback if sticking with the 2NH rotors. I don't plan to upgrade the rear rotors.

[HP Autosport]

Originally Posted by medphysdave

Seems like this would be one step towards helping with knockback if sticking with the 2NH rotors. I don't plan to upgrade the rear rotors.

You can upgrade the fronts only and match them with a good set of pads.

Feel free to PM or email us if you have any specific questions regarding Girodisc, Ferodo pads, or other brake products.

[ThreeStripes]

Originally Posted by NathObeaN

They also say if they deem the return rate to be ‘excessive’ beyond ‘reasonable lifetime’ then they won’t replace. I would imagine it wouldn’t last long before they say no.

For USA based folks reading along, fcp supports WRL race teams doing this so they’re fully aware of what users of the program are up to and aren’t going to cut you off unless you’re doing something insane.