Hi All,

I purchased an "aftermarket reproduction" Alcon style brake rotor from SNG Barratt. The rotors showed up today and I noticed the crescents are not drilled all the way through. Are the OEM rotors the same way?

See below! Thanks!

 

Same Same

 

On the OEM rotors I got from Suburban Autoparts, the crescents are cut through. They were actually Jaguar part numbers.

 

Do you have a picture by chance?

 

I just found a picture of the OEM rotors. It even has the "Jaguar" lettering if you look closely.

From the picture, it is not cut all the way through, same as the remakes.

 

OEM Jaguar Alcon rotors are grooved, and do not go all the way through the disk.

I know because my 2009 XKR Portfolio convertible has the Alcon Performance Brake Package, a $5,000 option, and am still using the original rotors. A few years ago, I replaced the pads only, without resurfacing the rotors because they were still in good shape.

I have a brand new set of Centric "Alcon" rotors and Brembo ceramic pads that I'll use when it's time for new pads. See:
Alcon Rotors Cheap
Unfortunately, it appears that they're sold out.

Brembo Ceramic Pads for Alcon Rotors

 

I purchased the same ones twice now. Only differences I noticed:
1. The shape of the grooves is different
2. There is no notch on the aftermarket ones like there is on the OEM ones - even though the manufacturer specifies they ARE machine balanced

Other than, that they are a great alternative for the super expensive OEM ones.

 

I guess I was lucky. I ordered all 4 rotors for my 2008 XKR Portfolio on line from Suburban Auto Parts on 2/10/2022

• Front Left: C2P10565
• Front Right: C2P10564
• Rear Left: C2P10563
• Rear Right: C2P10562

They actually shipped from Troy NY Jaguar in Jaguar packaging.
They all looked exactly like the originals and all the crescent grooves were cut all the way through.
Total cost of the 4 rotors was $3,123.29

 

Are you certain that the crescent grooves go all the way through the disk? If so, they're not the same as the original Alcon rotors.

And they might not be genuine. See:
Alcon Crescent Grooved Rotors Rotors

 

Stuart's correct. Drilled go through the braking surface to the cooling vanes at the core, grooved discs never ever go all the way through, typically machine grooves are just lightly deeper than wear thickness, for example Alcon front discs start at 36mm and are considered worn at 34mm, with the grooves just slightly deeper.

 

All the Alcon rotors I've had were grooved exactly the same way and notched. The grooves on the SNG supplied in the OP's post do not match OEM and having spoken with SNG, I was advised they were aftermarket supplied to only match OEM but were not OEM. The Centric sourced ones did not say Jaguar however Centric's buyer insisted their's came from the same OEM manufacturer's as Jaguar's. As far as I know, like many parts, none were ever actually manufactured by Alcon.

 

Does anyone know if these are painted or replaceable pieces on the Alcon rotors? One of my fronts and half of one in the rear are gone.

 

They’re painted.