Front setup: single rotor ? - Ducati.ms

Chouch · Apr 4th, 2011, 10:55 am

Hi all,
I beleive the Hypermotard 1100 was first designed and revealed with a single rotor setup.
And more recently, NCR and Hattar did that :

I'm wondering if there is any way to do the same kind of setup, without going crazy using Brembo HP caliper and CMC rotor ?

My idea would be a new Brembo T-drive rotor used with a M4 Monobloc.
Do you think it would provide enough braking power ?
Would I need to change the master cylinder for a different one ?

Any input is more than welcome.
If you want to share the price of a pair of M4, feel free to say so. Who know, maybe someone would like the same setup aswell.

vulpine3 · Apr 4th, 2011, 4:30 pm

First promo. pics of the Hyper showed it with a single disc on the front and a straight thru exhaust system that framed the engine beautifully. Pity Ducati didn't stay true to that lightweight stripped down version but the bike gained weight (that ugly cat...) & the market apparently demanded twin discs.

I reckon using a slightly larger than OE 320mm disc and spacing out a single monoblock could work well. You might lose a bit of ultimate braking performance but the trade off would be that you'd lose a fair chunk of unsprung/rotating weight.
You will need to reduce the diameter of the m/c in order to keep the right balance of power/feel.

Chouch · Apr 4th, 2011, 6:07 pm

So I need to search for a oversized rotor with the right offset.
Maybe a good set of Ferodo pads to use with Monobloc.

I'm looking at Brembo m/c and they have smaller diameter for a fair price (in their HP range, not the Racing line up)
Would a 16x18 or 16x20 be good ? Or maybe a 15RCS ?
I'm just curious, website such as OPPracing list them as good for bikes like GS500 or Ninja 250. Would it provide enough braking power for a 1100 Hyper ?

Chouch · Apr 5th, 2011, 11:02 am

So, it seems the Brembo T-Drive rotor offset is not an issue on the Hypermotard.
320mm diameter means all you need to add is 7.5mm spacer under the calipers.

Now I need to find a shop selling those not as a pair...

Still looking for more info regarding the master cylinder I should be using with a single front rotor.

Shazaam · Apr 5th, 2011, 11:55 am

Hydraulic Ratio:

Front Master Cylinder Ratio Chart

Chouch · Apr 5th, 2011, 12:44 pm

Thanks a lot for the link, it explains things pretty well.
So if I'm understand it well, I should be looking for a ratio between 27:1 and 23:1, but closer to 27:1 unless I want a firm lever, right ?

Bembo Monobloc M4 are out of charts... they are 4 pistons Ø 34mm, that's 3631.68 mm2

Wich means I should be looking for a 13mm master cylinder (which give a 27.50mm). A step bigger, 14mm gives a 23.73mm ratio
Now I just have to check if brembo offer such a thing.

edit: corrected the piston size on the M4, they are 4 pistons Ø 34mm

Caidly · Apr 5th, 2011, 5:11 pm

Quote:

Originally Posted by Shazaam

Hydraulic Ratio:

Front Master Cylinder Ratio Chart

What is that "area*mm²". I tried several numbers and it doesn't make sense.

NM, using: πr², I figured it out. But, how do I make sense of a caliper ratio of 19x20 for the chart?

Chouch · Apr 5th, 2011, 6:16 pm

Quote:

Originally Posted by Caidly

But, how do I make sense of a caliper ratio of 19x20 for the chart?

The way I understand it is that the area of all the pistons of your caliper(s) should be 27 time greater than the area of your master cylinder piston.

So in the case of your 19x20, that's a 19mm piston, giving us a 283.53mm² area.

If you apply the 27:1 ratio, you should go for a total caliper pistons area of 7655.31mm², or 3827.55mm² per caliper.
Brembo Monobloc M4 with their 4x 34mm pistons offer 3631mm² area and are a great match for a 19x20 master cylinder.

Hope this helps.

freezer16801 · Apr 6th, 2011, 5:39 am

what are you going to do with the other side caliper holes? Are you going to get a different wheel or just leave them alone?

Chouch · Apr 6th, 2011, 9:32 am

I dont know yet. I guess it depends on how well the setup will perform.
So far I'm having trouble to find a nice radial master cylinder with a 13mm piston.

I have 2 sets of forks, If the single rotor is a keeper, I wont mind cutting one of the caliper mount.
Unless I can find a 50mm fork bottom with no fork mount...
Worst case scenario, I use the caliper mount as a GoPro HD mount

But I'm really questioning the whole 27:1 ratio in Shazaam link.
I just looked at Beringer ssetp, and they are nowhere near this ratio at all.