Need front brake disc dimensions.

[psych0hans]

Hi guys, I was wondering which brake discs would be compatible with the RC390. Can someone measure the PCD and offset and post it here? It would be really helpful. I'm posting the RC8 disc dimensions for reference, as I have a strong feeling it might match, minus the offset. I would do it myself, but my bike is currently about 1000miles away and I won't see it for at least another 10 days... Thanks in advance.

RC8 Brake disc
Outer Diameter : 320 mm
Inner Diameter : 64 mm
Number of mounting bolts : 6
PCD : 80 mm
Thickness : 5 mm
Offset : 10 mm
Type : Floating

 

[psych0hans]

Does nobody have this data?

 

[chevaliernoir]

The offset is probably the most difficult to manage as the RC disk has no offset.
Adding offset on radial caliper would be a non sense, and I would not try to ass also offset for the disk itself...
I think it's a great idea, but not working, to my point of view...

 

[GOJO]

As i remember if you find the galfer disc on there website im sure it give dimensions

 

[psych0hans]

Just to answer my own question.

Outer Diameter : 300 mm
Inner Diameter : ?? mm
Number of mounting bolts : 6
PCD : 80 mm
Thickness : 5 mm
Offset : 0 mm
Type : ?

 

[chevaliernoir]

here is an interesting data base
http://www.eurospares.com/graphics/brakes/mc-front-rotor-sizes.pdf
320mm with 0 offset and 6 bolt is not so comon!

It could be interesting to check in detail the Triumph Thruxton 900...

 

[chevaliernoir]

hummm... looking deeper I become confused about the offset. Here is a definition of offset I've found from ISR brakes :

With this definition, a 5mm thikness rotor, completely flat would be considered to have 5mm offset...

 

[chevaliernoir]

GoldfrenUSA has the same offset definition :


So the front brake offset of our dear RC would be 5mm?

 

[SHOW SCARECROW]

Hello everyone
Report on the offset amount of the brake disk
When using the offset 7.5mm in outer diameter 320㎜ disc
Floating pin of the front fork and the disk is in contact at the time of brake
Therefore, the offset amount of disk should be kept in the up to 5 mm at the maximum
I was securing the offset amount of 5 mm to 2.5㎜ cutting the wheel side of the hub to use the Brembo disc for DUCATI (offset 7.5mm)

 

[SHOW SCARECROW]

We report the content is the maximum value when you change the radial mount fixing system to the axial mount system. (Maximum offset 5 mm)
Offset When using ordinary Baibure callipers must be 0mm

 

[chevaliernoir]

great adaption!
was the disk with the coirrect inside central hole, and with the same screws position?