Brake offset question

[techno]

I own an S2R800 and am in the process of doing the S2R1000 brake upgrade.

Can someone clarify the offset question for me?

My current discs appear to have no offset. By this I mean that the disc and carrier are both flat on the bench if you lay them down.

I ordered a 320mm set for the S2R1k and they have a definite offset (not sure of the size though). My first thought is they sent me the wrong ones but before I send them back I'd like to hear from someone who has done this mod.

Should the new discs have the same offset as the current ones on my bike (ie no offset at all)?

Cheers

[stopintime]

Don't worry.

(Assuming you also have new calipers from a S2R 1000)
You remove old calipers - you remove the bracket between the old calipers and fork legs - you put on new calipers - you discover that the new rotors must be off-set to meet the new calipers.

Are you replacing the master cylinder as well?
Already got new brake lines?

[Speeddog]

AFAIK, any Brembo caliper with the 65mm bolt spacing will work with the 320mm rotors.

[techno]

Don't worry.

(Assuming you also have new calipers from a S2R 1000)
You remove old calipers - you remove the bracket between the old calipers and fork legs - you put on new calipers - you discover that the new rotors must be off-set to meet the new calipers.

Are you replacing the master cylinder as well?
Already got new brake lines?

Thanks. I haven't tried that yet as the bike would be off the road while I got replacements. I am not planning to change the master cylinders as that would mean losing my CRG levers. I have some aftermarket braided brake lines. I will have to see if they fit as well.

[stopintime]

For the lines, it's the angle of the banjo fittings that matters. If yours are wrong, it could be difficult to find used ones that fit with new/bigger calipers AND a coffin master. PJ's Parts and Yoyodyne can build you a set for about $ 120.

Using your 15mm stock master will work, but the lever will feel a little soft and require a lot of movement. It will be VERY VERY important to get rid of ALL the air in the lines and to adjust the freeplay at the lever perfectly. Just so you know - Yoyodyne have the appropriate 16mm coffin master (keeping your CRGs), new for about $110. If your lines only fit a S2R1000 type master, it might be better to buy that kind of master than to buy new lines...

Do you have a picture of your lines?

This is a link to get the freeplay right: (scroll down)
http://www.ducatisuite.com/leverchange.html

A picture of this rotor/caliper set up to help you see what the lines will/must look like on the lower point.
The line(s), at the coffin point, should be straight or almost straight. Different with a S2R1000 style master.

[junior varsity]

don't forget about Spiegler for custom lines. That's who I have used for a bunch of lines. i've not had an issue, though I believe i remember somebody getting a mismeasured line. There's also Goodridge lines.

[Slide Panda]

If you've got the brake calipers from an S2R1000 then the rotors you want are 320mm with a 10mm offset. Your stock ones are 300mm with 0 offset. They have less, since the 2 piston calipers you have are mounted to an adaptor plate, not directly to the fork lower like in the photo above.

[junior varsity]

If you've got the brake calipers from an S2R1000 then the rotors you want are 320mm with a 10mm offset. Your stock ones are 300mm with 0 offset. They have less, since the 2 piston calipers you have are mounted to an adaptor plate, not directly to the fork lower like in the photo above.

Note: Due to that particular adapter plate's design, the offset goes to zero. A person using 65mm mount fork lowers, and the 65mm-to-40mm adapter plates (for using the 40mm billet brembos, isr, harrison, etc), would use the same rotors (and same offset) as with regular 65mm mount goldline calipers: the 6 bolt 10mm offset rotors.

Because I hadn't come up with a good reason to post this picture, I have found one now:
ISR 6 piston calipers using the adapter plates from AMS to mount on 998 forks, rotors are 10mm offset 6-bolt ISR dampened floating rotors

[stopintime]

About the 10mm offset rotors..... I went back and copied something i put together about the offset - it's not actually 10mm. This is not meant to confuse you - just showing you the reality, so you don't get confused if you start measuring. AFAIK, everyone call them 10mm even if they know they're not. It's just easier.

Offset is a strange story. The rotors I used are the ones commonly referred to as "10mm offset", but they are not actually 10mm. They are 5mm, 7mm, 9mm or 11mm depending on how they are measured.

5mm - on a table, outside up, measured from table to inside of rotor
7mm - as above, but measured to the middle of the 4mm thick rotor. This is how Brembo does it.
9mm - as above, but measured to the outside of the rotor
11mm - as above, but including the buttons

[junior varsity]

indeed. easy to way to think of the loose terms, based on OEM equipment:

10mm offset, 6 bolt pattern: for axial mounted calipers, examples: Brembo Goldline 4 piston 2 pad 1 pin 40mm mount, and Brembo Goldline 4 piston 2 pad 2 pin 65mm mount (oldest Monsters, oldest SBKs, oldest SS's |vs.| post 99 Monsters, SS, SBKs and the blah blah blah)

15mm offset, 5 bolt pattern: radial mount brembo monoblocs and 2-piece from the 848/1098/1198, 749R/999R, and the "yadda yadda"

Oddities:
998R has 15mm offset 6 bolt rotors iirc.


From seeing a 998 FE that was done to the fullest at the shop recently, it clicked that this is all really based on where the caliper mount is, horizontally, on the fork bottoms, combined with the caliper's mounting lugs. The 998 FE had billet fork bottoms and radial calipers, but was able to use 6-bolt 10mm offset floating rotors. I asked "why complicate the brake upgrade with billet fork bottoms, when you could just update forks to current SBK's and a current wheel"  - answer was high dollar matching mag wheels were already installed so making it work needed to be done

[orangelion03]

I just finished the same fork/brake upgrade to my 800 and found that one or both of the rotors are warped or bent 

[junior varsity]

bummer dude. significant pulsing or shuddering under braking or pulsating drag while rolling?

[techno]

OK, so I probably have the right discs.

the brake lines I was going to use won't fit. I got them for another bike (not a Duc) but never fitted them. The end that fits on the calliper doesn't have the right bend.

Looks like I will need to buy some before I do the mod.

[orangelion03]

bummer dude. significant pulsing or shuddering under braking or pulsating drag while rolling?

Under braking.  I took them off and put them on a surface plate, wheel mount surface on the granite.  Warp (on both) appears to be in only a portion of the disc, about a 60° arc.

[stopintime]

I just finished the same fork/brake upgrade to my 800 and found that one or both of the rotors are warped or bent 

http://www.yoyodyneti.com/ProductInfo.aspx?productid=08.4899.82