Ducati Monster Forum

Moto Board => Tech => Topic started by: dragonworld. on November 18, 2008, 04:14:45 PM

Title: Front Brake Disc
Post by: dragonworld. on November 18, 2008, 04:14:45 PM
I've had enough of the shudder in one of the front discs on my 2003 DS and I'm looking to replace it!! [roll]

Sooooo does anyone have an idea what other Ducs share the same disc, just to open the options. ;)

And is it worth replacing the discs with aftermarket items as compared to genyooowine ones with the factory built in shudder?? [roll]

Title: Re: Front Brake Disc
Post by: Slide Panda on November 18, 2008, 04:22:57 PM
So a M1000?  If so you've got a looooot of ducs that share that rotor.  They are 320mm 6 bolt w/ a 10mm offset.  All Monsters until 2005 shared the same rotors.  In '05 the 300 0mm offset rotors to go with the 2 piston calipers seen on the 620, 695 and S2R800 hit the scene.

Also any of the 748 and 9*6 rotors are a match.  SuperSports and SportTours will also match up.
Title: Re: Front Brake Disc
Post by: dragonworld. on November 19, 2008, 05:30:40 AM
Yep M1000DS, Thanks a bunch Yuu [thumbsup]
Title: Re: Front Brake Disc
Post by: Speeddog on November 19, 2008, 07:11:24 PM
BrakeTech, iron or stainless.  8)
Title: Re: Front Brake Disc
Post by: krista on November 23, 2008, 11:37:54 PM
Yes, the standard brake discs are pretty thin (4.5mm) while all the aftermarket ones are 5mm.

My personal opinion is that the standard rotors are a bit too thin to shed all of the heat that the brake pads generate. Sometimes they will get a temporary heat-induced warpage. And rarely, that temporary warp sticks. I've had some amazing luck with my history and did exactly that to my MH900e... :P Aw well.

;D Chris
Title: Re: Front Brake Disc
Post by: greenmonster on November 24, 2008, 06:53:29 AM
QuoteIn '05 the 300 0mm offset rotors to go with the 2 piston calipers seen on the 620, 695 and S2R800 hit the scene.

Slight threadjack:
Do the 300mm´s have the same bolt pattern as most older 320mm discs (like for 916-748, SS & Monsters from the 90`s) ?
How much differs in offset 300-320?
Just courious if the newer 300mm will fit 1991 wheel on my 907, w addition of an offset spacer.
Title: Re: Front Brake Disc
Post by: Slide Panda on November 24, 2008, 07:48:50 AM
Quote from: greenmonster on November 24, 2008, 06:53:29 AM
Slight threadjack:
Do the 300mm´s have the same bolt pattern as most older 320mm discs (like for 916-748, SS & Monsters from the 90`s) ?
How much differs in offset 300-320?
Just courious if the newer 300mm will fit 1991 wheel on my 907, w addition of an offset spacer.

Yes, 6 bolt.  10mm-0mm = 10mm  ;D  So there's the difference.

I guess it could fit - but you'd need different calipers too.. unless you'd want to NOT use 10mm worth of the rotors face...  Which would do bad things to pads I'd think
Title: Re: Front Brake Disc
Post by: greenmonster on November 24, 2008, 08:44:22 AM
QuoteI guess it could fit - but you'd need different calipers too.. unless you'd want to NOT use 10mm worth of the rotors face...  Which would do bad things to pads I'd think

That´s were the offset spacer would come in handy between rim-disc, but maybe 10mm is too much/unsafe?
Anyone done somethiing similar?
Title: Re: Front Brake Disc
Post by: Slide Panda on November 24, 2008, 09:00:14 AM
I'm referring to the fact that you're thinking of using 300mm rotors - in conjunction with a caliper set up spec'd for 320mm rotors.  Currently, you rotors outer edge should extend a bit past the outer edge for your brake pads... but if you reduce the rotor size by 20mm (diameter) now the outer edge of the rotor will probably not extend beyond the outer edge of the pads. 

I got that you were thinking of using a 10mm shim or something to make up for the offset... which I also don't think is such a hot idea.  As a result, you'd be using longer bolts to secure the rotors... longer bolts = longer levers.  So by this fact, you'd be adding a lot more stress to the bolts and wheel hubs on a critical component.  I'd hate to see the hub or bolts give out, that'd make for a terrible crash.
Title: Re: Front Brake Disc
Post by: Duck-Stew on November 24, 2008, 11:19:52 AM
They're ultra rare, but 748R's and other super high performance SBK's ran a 15mm offset so there's a slight difference.  Otherwise, yuu's statement of rotor fitment is correct.
Title: Re: Front Brake Disc
Post by: krista on November 24, 2008, 01:58:44 PM
Quote from: greenmonster on November 24, 2008, 08:44:22 AM
That´s were the offset spacer would come in handy between rim-disc, but maybe 10mm is too much/unsafe?

Quote from: yuu on November 24, 2008, 09:00:14 AM
I got that you were thinking of using a 10mm shim or something to make up for the offset... which I also don't think is such a hot idea.  As a result, you'd be using longer bolts to secure the rotors... longer bolts = longer levers.  So by this fact, you'd be adding a lot more stress to the bolts and wheel hubs on a critical component.  I'd hate to see the hub or bolts give out, that'd make for a terrible crash.

Actually, there is never a shear load on the bolts, so "leverage" is not an issue. Should there ever be need for "leverage" the bolts will all shear off. What makes the brake rotors work is the clamping force of the heads against the rotor creating friction between the rotor and the wheel hub. A single M8 fastener torqued to 15 ft-lb provides some 2857 pounds of clamping force. 6 of them gets you over 17000 pounds of clamping force. That's what keeps the rotor in place.

What about a 10mm spacer? The real issue is not the load or length of screws rather the ability to properly center the rotor about the hub. I have 5mm spacers between the Ducati rotors and the Ducati front wheel on my MH900e that I just put GSXR forks onto. Either one or neither of the rotors is actually overlapping the raised center portion in the hub. I have had no problems with that setup (nor have I heard anything from other GSXR swap riders).

:) Chris
Title: Re: Front Brake Disc
Post by: Slide Panda on November 24, 2008, 02:18:35 PM
Quote from: Duck-Stew on November 24, 2008, 11:19:52 AM
They're ultra rare, but 748R's and other super high performance SBK's ran a 15mm offset so there's a slight difference.  Otherwise, yuu's statement of rotor fitment is correct.

Hence my sneaky *most* in the 1st post.

Quote from: chris on November 24, 2008, 01:58:44 PM
Actually, there is never a shear load on the bolts,

I stand corrected on that point.  So adding spacers, not an issue.  But the fact the rotors too small a diameter... still an issue.
Title: Re: Front Brake Disc
Post by: Duck-Stew on November 24, 2008, 02:30:15 PM
Quote from: yuu on November 24, 2008, 02:18:35 PM
Hence my sneaky *most* in the 1st post.

You sir, and indeed sneaky.  ;)
Title: Re: Front Brake Disc
Post by: jerryz on November 24, 2008, 08:41:04 PM
Convert the old disc to fully floating with the big hammer technique ..it works .
Title: Re: Front Brake Disc
Post by: greenmonster on November 25, 2008, 08:16:39 AM
QuoteI'm referring to the fact that you're thinking of using 300mm rotors - in conjunction with a caliper set up spec'd for 320mm rotors.

Guess I left out vital info: My interest in the 300mm´s is thats what the 1991 907 is using, not 320.
300 w standard offset is quite rare these days, thereof my questions. I am aware of the caliper conversion bracket possibility.


If using a 8-10mm spacer, anything to think of when choosing bolts?
Is alu OK as spacer material or should it be of steel?
Title: Re: Front Brake Disc
Post by: krista on November 25, 2008, 04:29:20 PM
aluminum spacer and stainless bolts should work out well. I have a source for aluminum tubing that might make a great starting point for the machining of the spacers.

oops scratch that. The tubing has an ID of 4". The tubing we'd need is like ID = 2.5", OD = 4" and 6 holes on an 80 mm circle... :P

Kinda close.