Earlier this year I fitted a new EBC floating disc with EBC sintered pads to the back of the outfit. Consequently, the back brake has improved beyond all expectations; so much so that I have been braking hard just for the pleasure of feeling the retardation. I soon noticed that the disc was turning a nice shade of blue, fading to light straw at the rim. Ahah, it must be dragging, thought I, but no, in fact the wheel spins freer than it ever has in the past.

Now with all this braking energy, considering the extra weight of an outfit, the resulting heat must be going somewhere, and when I changed the back tyre recently this is what I found:-



That caliper has been getting pretty hot.

No problems with fade or fluid boiling so far, but I am keeping an eye on things.

Paul.

wow!

My brother put an EBC disk and brake pad on his RT, and a month later, he had to replace it.
Same problem, the disk was overheating and warped.

Sorry for the bad news, but I believe that it's a design flaw. If it was the same problem on a computer, Microsoft would call this a 'feature'


CF

Was your brother's a floating disc CF?

sidecar paul wrote:Was your brother's a floating disc CF?

I am not sure. This is what EBC sold as a replacement for a 1985 back brake.

Probably a solid disc then.

One of EBC's claims for the floaters is that they are less prone to warping. Anyway no problems for me with warping........so far. We'll see how it goes.

Paul.

good info paul thanks .

but it kinda makes sence, better braking means the extra heat generated is absorbed somewhere huh ?

im guessing the new disc is not stainless or a different variation of the original ?

Floating discs will run much hotter especially on heavier bikes because much less heat transfer to the wheel hub.

Floating rotor discs aren't necessarily less prone to warping than their
solid counterparts, but they may be more so because heat can't transfer
away from the disc surface and through the carrier as easily. The
reason that fully-floating rotors exhibit fewer warpage symptoms is that
the pretensioning springs allow for a bit of flex between the disc and
carrier. As such, a fully-floating rotor would need to be very badly
warped to exhibit symptoms of warping.

Read more: Motorcycle Floating Brake Rotors Vs. Solid Mounted | eHow.com http://www.ehow.com/info_12040134_motorcycle-floating-brake-rotors-vs-solid-mounted.html#ixzz2HYf6gU1U

Hi Charlie, I've just looked at EBC's site and the disc is "forged billet steel".

Surface rust does appear, but not much more than the "stainless" Grimeca front discs that I have, and certainly not as bad as cast iron discs.

A good brake is my primary concern, so I'll put up with the odd melted plastic cover provided no other problems crop up. Maybe I'll make a stainless cover at some stage.

Paul.

Hope you're keeping cool. ......we're trying to keep warm.

Aha the magic word billet I recall looking through a friend's HD accessories catalogue and just about any metallic object had the word billet added to the description as if it were a mark of quality An interesting thought about the ability to transfer heat being greated with soldi rotors rather than the bobbins, I had not thought about that previously but it sound totally logical.

One thing I have never understood was the fashion for sculpted rotors which have big chunks nibbled out of the periphery all the way round, it seems counter intuitive to me since although it reduces unsprung weight marginally, it reduces braking ability a definitely negative trade-off in my book. Happy to be corrected if anyone knows a technical reason for sculpted rotors on a road bike.
Regards,
K-BIKE

when I was drag racing and winning most of the time if I had changed the anodized fittings from red to blue most of the other competitors would follow suit. It is very easy to make something that is totally useless into a must have item with the right advertising. All the numpties will follow along and throw the money at you and tell every body they come across how good said useless item is and the more they pay the better it is.
As my sponsor used to say Viva la mug

K-BIKE wrote:One thing I have never understood was the fashion for sculpted rotors which have big chunks nibbled out of the periphery all the way round......
K-BIKE

The only new development on break that I was impressed with was on the Buell.
I never tried one, but it certainly look good on paper: Big contact surface increasing the breaking power and heat dissipation. It must be way better than the sculpted rotors.

K-BIKE wrote:One thing I have never understood was the fashion for sculpted rotors which have big chunks nibbled out of the periphery all the way round, it seems counter intuitive to me since although it reduces unsprung weight marginally, it reduces braking ability a definitely negative trade-off in my book. Happy to be corrected if anyone knows a technical reason for sculpted rotors on a road bike.
Regards,
K-BIKE

Never thought about it before but it would increase the surface area of the outer rim of the disc and possibly increase the cooling capacity?
Warranted on a road bike?
Probably aesthetics.

Yes K bike, "billet" is used as to infer magic properties in some catalogues, but it's really a good Old English word, derived, via French, from mediaeval Latin. It originally meant a block of wood, but later was applied to blocks of metal, so any thing that is produced from a solid block is quite entitled to be refered to as billet.

Paul.

[quote="K-BIKE"]One thing I have never understood was the fashion for sculpted rotors which have big chunks nibbled out of the periphery all the way round, it seems counter intuitive to me since although it reduces unsprung weight marginally, it reduces braking ability a definitely negative trade-off in my book. Happy to be corrected if anyone knows a technical reason for sculpted rotors on a road bike.
Regards,
K-BIKE
[/quote]

I asked the same thing of Sandro, the President of Galfer USA. The multitude of edges cleans the pads, disperses dust and water and improves cooling. It is also lighter. There is some good engineering behind them.

If you have a rear rotor overheating like that, I would investigate the orifice in the rear master cylinder. Over time fung will accumulate in the orifice and this restricts the ability of the piston to return, allowing the pads to drag on the rotor and overheat it. Take the piston out of the rear master cylinder and clean it thoroughly. Run some small guage wire through the orifice and blow it out to ensure it is open.

The other place to look is the rear brake reservoir. You have to leave some air in the top to permit fluid expansion when everything back there warms up. If you fill the reservoir to the very top and screw the lid on tight, as you ride and things warm up, fluid expansion causes the rear pads to engage. If you leave some room in the reservoir, the fluid can expand into the empty space in the reservoir.

Crazy Frog wrote:

K-BIKE wrote:One thing I have never understood was the fashion for sculpted rotors which have big chunks nibbled out of the periphery all the way round......
K-BIKE

The only new development on break that I was impressed with was on the Buell.
I never tried one, but it certainly look good on paper: Big contact surface increasing the breaking power and heat dissipation. It must be way better than the sculpted rotors.

In the Harley Davidson Museum there was a display of prototypes that never made production. Among the bikes displayed was a V-4 Nova sport bike circa 1982 with perimeter braking. That is how old the idea is.

http://www.motorcyclistonline.com/newsandupdates/motorcycle_news/122_1109_harley_davidson_museum/

Audi's infamous "UFO Brakes" were another attempt at perimeter brakes.

http://www.spannerhead.com/2011/10/21/technical-curiosities-audis-ufo-brakes/

Ghezzi and Brian, an Italian race shop that specialzes in road racing Moto Guzzis and hot street Guzzis offered bikes with dual perimeter brakes and an under the engine muffler just like Buell uses, only they considerably pre-dated Buell with these features.

Thanks guys,
Most interesting I love the look of the Guzzi if only it was red.
Regards,
K-BIKE

"...if only it was red"

K-BIKE clearly is a man of good taste!

Who cares if the perimeter brakes offer better performance or not, the just look damn hot!

I've got 'perimeter' brakes on my bicycle.

With sleet and snow in the air this morning, I sorted out an old caliper and made a stainless steel caliper cover. Now that shouldn't melt......



Paul.

Spot weld some fins on that will make a self cooling heatsink. Neat job.

Do you get satisfaction now?

OK, OK, I'll "Paint it Black" to your "Satisfaction"

A rolling stone gathers................momentum. (MAD magazine circa 1958)

Paul.

But did you check to make sure the master cylinder orifice is open so the piston can return and allow the pads to back off the rotor fully???

Read my first post, THEY ARE FREE.