The axial mount Yamaha mono block calipers are a popular front brake upgrade for our FJ's.
I've always wondered what the differences were between the different model monoblock calipers.
I happen to have 2 calipers to compare the differences, the gold spots off a 2002 YZF-R-1 and the blue spots off a 2002 FZ-1
The R-1 gold spots have thicker wall (0.5mm) aluminum pistons
(http://fjowners.com/gallery/10/49_02_02_17_11_23_22.jpeg)
The FZ-1 blue spots have a thinner wall (0.2mm) steel pistons
(http://fjowners.com/gallery/10/49_02_02_17_11_26_26.jpeg)
The bodies look identical. The piston diameters look to be the same, 2.6mm leading, 3.0mm trailing. Same brake pads and hardware.
A big difference is the cost of the piston seals, for a pair of the FZ-1 blue spots you will spend over $90, for a pair of the gold spots $26.
Have any forum members noticed a performance difference between the Blue Spots vs the Gold Spots?
There may be a very slight weight difference between the two, but honestly I wouldnt think there would be any advantage one way or the other?
Well, maybe the cost difference in the seals that you noted.
I happen to have the gold ones, but pick whatever color you like.
When searching for a used set of either, I think the blue ones are easier to find. They were available on a greater variety of bikes?
There are also silver ones out there as well.................
Good eye for detail Patrick!
I went from a set of Blue Dots to the Silver Dots.
I never noticed any difference at all.
Midget.
Hey Alan, I did not pop out the pistons to weigh them, so I don't know if there is any weight savings between the aluminum vs. steel pistons.
My (uninformed) thoughts on why there is a piston difference between track spec'ed R-1 vs. the street spec'ed FZ-1 is *perhaps* there is an advantage to having the thicker wall aluminum pistons pressing against the brake pads? More of a surface area pressing against the back plate of the pads? Better uniform loading?
I also noticed on the Gold Spots there was a stainless plate which fit on the back side of the oem brake pads, heat isolation?
With the larger surface contact area, I wonder if the thicker aluminum pistons are more susceptible to heat transference, thus the need for back plates?
I'm open for thoughts...
Mike, yes, I know about the silver spots, according to the parts fische, they also use the same steel pistons as the blues...
Quote from: Pat Conlon on February 02, 2017, 04:13:41 PM
the larger surface contact area I wonder if the thicker aluminum pistons are more susceptible to heat transference, thus the need for back plates?
My guess is that the aluminium pistons dissipate heat a lot quicker than the steel pistons. This should help with the cooling of the calipers.
I'll throw my hat into the ring on this...
1) I have rebuild several blue, gold and silver pot calipers and so far i have been able to use the same rebuild kit on all of them. I used the have the kit posted on the website, but I can't find it now. I will get it reloaded.
2) Aluminum is used to keep the amount of dis-similar metal in the system to a minimum. The problem is actually opposite of what Pete mentioned as far as heat. The aluminum pistons do conduct the heat much quicker, right to the brake fluid. The piston does not have a good contact patch of heat transfer into the caliper body, so the heat transfers to the fluid quicker that steel pistons.
Now, steel pistons have to be chrome plated to prevent rusting and that is an added cost to the manufacture.
3) I would say the stainless pad was more of a heat insulator/wear protection for the aluminum pistons. Stainless does not transfers heat very well and wear much better than aluminum.
Randy - RPM
Thanks Randy, that's interesting that the same seals can be used on the aluminum and steel pistons.
It's kinda like the clutch springs....the crazy price for the FJ spring and the more reasonable price for the FJR.
So ...good to know, instead of ordering $90 worth of seals for the blue spots, order the $26 gold spot seals.
Quote from: Pat Conlon on February 02, 2017, 04:13:41 PM
.....there was a stainless plate which fit on the back side of the oem brake pads, heat isolation?
With the larger surface contact area, I wonder if the thicker aluminum pistons are more susceptible to heat transference, thus the need for back plates?
I'm open for thoughts...
Pat, the only thin SS plates I've ever seen between the pad and the pistons are anti squeal shims.
Noel
Hi Noel, yes, I'm familiar with the anti squeal shims for cars, however I'm fairly certain these shields are for heat.
Here's a set of EBC HH pads with the heat shields included
(http://rpmracingca.com/prodimages/large/M%20C%20FA252HH-1.jpg)
Quote from: Pat Conlon on February 02, 2017, 11:53:58 AM
Have any forum members noticed a performance difference between the Blue Spots vs the Gold Spots?
I am running blue dots with HH Sintered pads and rubber lines on one bike and gold dots HH Sintered pads and Braided lines on the other.
Both with FJR masters.
The gold dots deliver better braking and feel .The only difference is the lines.
I'm about to put new rotors and pads on the blue dots. Will see if this brings them up to par.
Quote from: oz.fj on February 05, 2017, 04:47:17 PM
Quote from: Pat Conlon on February 02, 2017, 11:53:58 AM
Have any forum members noticed a performance difference between the Blue Spots vs the Gold Spots?
I am running blue dots with HH Sintered pads and rubber lines on one bike and gold dots HH Sintered pads and Braided lines on the other.
Both with FJR masters.
The gold dots deliver better braking and feel .The only difference is the lines.
I'm about to put new rotors and pads on the blue dots. Will see if this brings them up to par.
You say "
The gold dots deliver better braking and feel .The only difference is the lines"'
They are the difference.
New rotors and pads will not bring the blue dots up to the gold dots as long as you have rubber hoses feeding them.
I'm not aware of any technical reason why the golds would be any better than the blues, changing over to braided hoses should (all things being equal) make them identical, they make a big difference, in fact, the very difference you describe.
IMO
Noel