Drilled disc

bluej58 wrote: I switched to dual drilled disks on my bike because I could not get the single non drilled disk to quit squealing when I stopped :pinch:

My back brake has done that forever.

Ceramics transfer heat??? Not with the physical laws in place in this universe.
Exactly the opposite is true, ceramics transfer very little heat, they are actually a great insulator. Just a quick example: If you know someone with ceramic coated headers, touch the header while the engine is running. You'd expect to get burnt, but you don't, it may be warm, but it sure won't burn you (Street use, never tried it on a high horse race motor). Adiabatic engines have been built from ceramic, that's engines that require no cooling because there is no heat transfer through the ceramic.

Next correction: Way back when the 750 Honda Four came out with disk brakes, the racers discovered that when the brakes got hot they suffered pretty serious brake fade. Problem was the gas outgaussing from the pads at high temps was creating a buffer between the pad and the disk. Solution was to drill the disk to allow the gas to escape quickly. It worked and rapidly Joe Kool copied it for his streetbike because it looked cool. Side effect was weight reduction, and drilling removed mass which increased the tendency to warp. And every hole you drill reduces stopping power a small amount, drill enough holes and you'll have zero stopping power

Ok, I know this stuff because I'm older than dirt and I was there. :laugh:

steell wrote: Ceramics transfer heat??? Not with the physical laws in place in this universe.
Exactly the opposite is true, ceramics transfer very little heat, they are actually a great insulator.
Ok, I know this stuff because I'm older than dirt and I was there. :laugh:

They also used ceramic tiles on the nose of the space shuttle to keep the glowing orange plasma trail from cooking the occupants on re entry. Seemed to work pretty well.....

However, not all ceramics are the same. Some are optimized for heat transfer (conduction):

global.kyocera.com/fcworld/charact/heat/thermalcond.html

steell wrote: Ceramics transfer heat??? Not with the physical laws in place in this universe.
Exactly the opposite is true, ceramics transfer very little heat, they are actually a great insulator. Just a quick example: If you know someone with ceramic coated headers, touch the header while the engine is running. You'd expect to get burnt, but you don't, it may be warm, but it sure won't burn you (Street use, never tried it on a high horse race motor). Adiabatic engines have been built from ceramic, that's engines that require no cooling because there is no heat transfer through the ceramic.

Next correction: Way back when the 750 Honda Four came out with disk brakes, the racers discovered that when the brakes got hot they suffered pretty serious brake fade. Problem was the gas outgaussing from the pads at high temps was creating a buffer between the pad and the disk. Solution was to drill the disk to allow the gas to escape quickly. It worked and rapidly Joe Kool copied it for his streetbike because it looked cool. Side effect was weight reduction, and drilling removed mass which increased the tendency to warp. And every hole you drill reduces stopping power a small amount, drill enough holes and you'll have zero stopping power

Ok, I know this stuff because I'm older than dirt and I was there. :laugh:

There must be different types of ceramics. The type I referenced dissipate heat extremely quickly.

I suggest you take another look at my posting and the video. As I stated “This isn't a brake application, but it's a block of ceramic that has been in a 2,200 degree oven for hours. Pull it out of the oven and pick it up right away with your bare hands - now that's something that is dissipating heat quickly!”

If you watch the video pay special attention to the part that begins around time 0:30. I suspect this guy knows what he’s talking about when he says it dissipates the heat quickly as he picks up that ceramic block that just came out of the oven. Otherwise he would be jumping around yelling OUCH OUCH OUCH! :laugh: :laugh: :laugh: Ed

There must be a different ceramic type or some blend used in the brake rotors because they do dissipate heat very well. Here's a quote from the link below...

“Carbon ceramic brake rotors offer tremendous heat dissipation benefits simultaneous with very low mass,” says Ron Younkin, Chevrolet’s engineering manager of brakes...

www.autoguide.com/auto-news/2012/10/why-...-ceramic-brakes.html

steell wrote: Ceramics transfer heat??? Not with the physical laws in place in this universe.
Exactly the opposite is true, ceramics transfer very little heat, they are actually a great insulator. Just a quick example: If you know someone with ceramic coated headers, touch the header while the engine is running. You'd expect to get burnt, but you don't, it may be warm, but it sure won't burn you (Street use, never tried it on a high horse race motor). Adiabatic engines have been built from ceramic, that's engines that require no cooling because there is no heat transfer through the ceramic.

Next correction: Way back when the 750 Honda Four came out with disk brakes, the racers discovered that when the brakes got hot they suffered pretty serious brake fade. Problem was the gas outgaussing from the pads at high temps was creating a buffer between the pad and the disk. Solution was to drill the disk to allow the gas to escape quickly. It worked and rapidly Joe Kool copied it for his streetbike because it looked cool. Side effect was weight reduction, and drilling removed mass which increased the tendency to warp. And every hole you drill reduces stopping power a small amount, drill enough holes and you'll have zero stopping power

Ok, I know this stuff because I'm older than dirt and I was there. :laugh:

Great info ! thank you Steell
Now can you tell me why Kawasaki drilled their disks in the strange order that they did :huh:

JD

It's all about looks on street bikes. Way back when, the Bike Mags published drilled disk diagrams, and also had articles on how to do it yourself.
Bet if you do a search for drilling brake disks you'd find a bunch.

During another when, at the time that disk brakes for bikes were developed, the hot ticket was a 8 "eight", that's right "8" leading shoe front brake. Everyone hated adjusting the things, and rejoiced when disk brakes became available. (In UK, don't know about US, no Net back then).

650ed wrote: There must be a different ceramic type or some blend used in the brake rotors because they do dissipate heat very well. Here's a quote from the link below...

“Carbon ceramic brake rotors offer tremendous heat dissipation benefits simultaneous with very low mass,” says Ron Younkin, Chevrolet’s engineering manager of brakes...

www.autoguide.com/auto-news/2012/10/why-...-ceramic-brakes.html

I didn't know about the high transfer ceramics, so thanks for telling me, it's a good day when I learn something new.

High rate of heat transfer means if you hold a torch on one side of a substance, then put your hand on the other side, you get burnt. The ceramics I am familiar with are outstanding insulators, like my explanation of headers, and the adiabatic engine (no cooling system, no heat transfer (just think about how many hp you could gain if all of the heat was transfered to producing hp).

If you're going to dissipate heat, then first you must absorb the heat, so they must use the heat absorbing ceramic you mentioned. I'm just emerging from a three year waking coma, so I may be wrong, but I thought the GP bikes were using Carbon Fiber disks and they had recently been banned. Am I three years out of date?

From the above link:

At high temperatures, carbon ceramic materials are also less resistant to deformation or warping, which means that they should last a bit longer than traditional brakes.

Think a proofreader was not hired? Or am I still in that waking coma, cause it makes no sense to me.

bluej58 wrote:

steell wrote: Ceramics transfer heat??? Not with the physical laws in place in this universe.
Exactly the opposite is true, ceramics transfer very little heat, they are actually a great insulator. Just a quick example: If you know someone with ceramic coated headers, touch the header while the engine is running. You'd expect to get burnt, but you don't, it may be warm, but it sure won't burn you (Street use, never tried it on a high horse race motor). Adiabatic engines have been built from ceramic, that's engines that require no cooling because there is no heat transfer through the ceramic.

Next correction: Way back when the 750 Honda Four came out with disk brakes, the racers discovered that when the brakes got hot they suffered pretty serious brake fade. Problem was the gas outgaussing from the pads at high temps was creating a buffer between the pad and the disk. Solution was to drill the disk to allow the gas to escape quickly. It worked and rapidly Joe Kool copied it for his streetbike because it looked cool. Side effect was weight reduction, and drilling removed mass which increased the tendency to warp. And every hole you drill reduces stopping power a small amount, drill enough holes and you'll have zero stopping power

Ok, I know this stuff because I'm older than dirt and I was there. :laugh:

Great info ! thank you Steell
Now can you tell me why Kawasaki drilled their disks in the strange order that they did :huh:

JD

I'll wager that pattern is not done at random but to balance the disc. They probably drill a set pattern then put it on a balance wheel and measure the angle between two points on the disc and then there is a table to show where to put the last holes.

I still remember a homework problem I had to do as to how they balanced the spinning cups inside of the old mechanical speedometers. They would drill a hole, let it rotate and measure the angle between the hole and vertical and based on that there was a complicated derivation as to where to put the second hole to have it be balanced.