Ducati Monster Forum

I was reading this month's Sport Rider and they talked about the 2012 Streetfighter 848's non-monobloc Brembo caliper. It looks similar in design to the calipers on my 696, which looked to me like they were cast? and 1 piece. But then I tried to find a comparison but only found photographs that showed various caliper designs that looked the same to me except for some monoblocs being machined vs. cast.

What's the specific difference in design and manufacture? I think the Brembos on my Cobalt SS Turbo are monobloc because they look machined. The Brembos on my 696 look/feel cast but I can't see how they bolt together.

Monoblock are machined from one piece of metal.

Most are billet.

2 piece are exactly that:  two halves bolted together.  No matter how tightly you bolt them, they can shift some under high stress and heat.

Monobloc:

no seam.  No bolts holding the halves together:
(http://tgp-racing.com/files/brembo_monoblock_p4_34-34_750x.jpg)

P30/34:  Old style 2 pad 4 piston:  2 bolted halves, Bolt heads on the OUTSIDE
(http://www.motorcycle.com/images/content/Event/brembo_2pint.jpg)

P4/34: later style 4 pad 4 piston, 2 bolted halves, bolt heads on the INSIDE
(http://apriliafalco.hadeler.net/images/article_images/4pad_brembo/caliper.jpg)

Ah, that makes a lot more sense. So if it is cast, there's a better than good chance it is 2-piece and if it is machined, it is most likely monobloc?

I don't recall the seam on my 696 calipers, but I can check later in the day.

i don't think the cast vs machined is the issue.  a cast item can be machined in finish, this is standard for things that are investment cast.

the monobloc i posted is machined from a billet of aluminum. 

the issue is solely whether you have a seam and bolts holding the halves together. 

most of the radial mounts are monobloc, almost all of the axial mounts are 2 halves. 

How do I tell if it is radial or axial mount?

Radial - the bolts holding the caliper to the fork will be parallel to the rotors face. Axial they are perpendicular.

1st photo is a radial caliper. 2nd and 3rd are axial mounts

Everything is clear now, thanks

The new Dalai Lama?  :o

 ;)

Easiest way to differentiate - cost. Monoblocs are ridiculous. Overkill in every way, but beautifully crafted items indeed.

It's true.  For racing, I would say they are necessary as they really do provide a benefit, but for street they are just bling

I recall and just checked that my stock Brembo calipers on the 09 696 are radial mount, but they look cast.

My stock Brembo 4-piston calipers on the Cobalt look machined, but checking online, it is axial mount. I don't see any type of seam on those calipers though, and I don't recall any seams on my 696 4-piston calipers - but magazines/articles stated that the Cobalt received monobloc Brembo calipers.

Real monoblock calipers are VERY expensive - a base model like the 696 isn't going to have them. Two piece calipers are a lot easier to make, hence the lower cost.

The Cobalt? Like Chevy?

So what does the 696 have? Radial mount 2-piece Brembo calipers? I guess I'll have to look more closely for the seam.

Yes, the 08-10 Cobalt SS Turbocharged, with factory 4-piston Brembo front brakes (Ferodo pad compound). They look machined, with black anodizing, and they are axial mounted from the looks of it. I cannot find any seams though, but it isn't as exposed as a motorcycle. The magazines/articles said those are monoblock calipers.

It's true! Monoblocs on a Cobalt. The wonders never cease.

Isn't a Cobalt an updated Cavalier or something?

That SS Turbo is actually a pretty hot little car. Hot as in rodded, not neccessarily hot as in hot.

It's a bit of a stretch to realize GM would put Brembo Monoblocs on a Cobalt, but that's what appears to have happened in the case of the SS Turbo. Maybe all SS Cobalts. Those are $23,000 cars. :o

From the photos I looked up - they are cast and anodized or painted on the chevy. They appear to have external hoses linking the two halves, so they could well be a single casting, that's externally plumbed. Those external hoses would do a lot to keep the costs down. There may be some machine work done - but they won't be billet.

So it seems the Cobalt has monoblock calipers, but they are cast and externally plumbed

Any billet parts start of as a solid block of metal and an subtraction is done via CNC or other machine process. Cast parts are, well, cast into the rough shape and minimal machine work is done to ensure proper sizes, threadings etc.

Billet Moto-mono blocks (like the first photo) have all the passages inside, which takes a lot of fiddly, time consuming machine work. Time = money.


The 696 has Radial 2-piece calipers

I think all the time/money is in the finish.

the internal passages are bored from the inboard side and then plugged.

Isn't there a further differentiation, as in forged monobloc? Or is the term forged to be used interchangeably with billet? Which is the mostest- billet or forged?

...which are pretty damned good anyways :-*

On the SS Turbo, the external crossover is a hard line that runs underneath the caliper (when looking through the wheel). I believe the Wilwood 4-piston caliper used on the latest HMMWV has a similar crossover line. A lot of performance cars these days run Brembo calipers, it's pretty common to see nowadays. The Cobalt is built on the Delta I platform, while the Cavalier was J-Body. Delta II is now used for the Cruze and Volt (which replaced the Cobalt).

I looked at the Ducati parts manual and see the bolts for the 696 calipers on the inside (inboard side of each caliper) even though they are radial mount, so it is indeed a 2 piece.

Mounting style and caliper construction aren't related. There were monoblock axial calipers too. Monoblock just describes the construction of the caliper while radial/axial describes how it's mounted.

All metal starts out as cast into a billet (square) or a round (ball)

Forging is the process of making a rough shape out of softened billet or round.  It is heated until soft enough to be malleable.  The most common process is Hammer Forging where the shape is literally stamped.  After being forged, the part is then finished using a cutter or CNC. The process of hammering while the metal is soft changes the grain structure and relieves internal stress.

Aluminum and steel can both be hammer forged, but it's less common to see it.  Forging produces a super high strength part because it aligns metal grains and stuff like that.

The monobloc are CNC cut from an aluminum billet and finished.  The process has several cutting steps.

I don't know of any hammer forged parts on the bike except for the crank and maybe the rods.

forged rims too

Forged on some, yes.  Not hammer forged though.