brake info (not to the faint of heart)

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addicted to relics
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brake info (not to the faint of heart)

#1 Post by addicted to relics » Wed Aug 22, 2018 8:46 pm

ok I will get info out there that most don't know

its a copy from another thread

Not a lot of people know this but the reasoning of drilled / slotted rotors and why it looks cool and racy, it Is a fucking bummer, am about to crush your world down so bad am so sorry.

The pads from the 50's and 60's were new and bad technology, when heated, they created gases between the pads and rotors, not ideal when you want to brake to have a pocket of gas between your pads and rotors, hence the drilled and slotted rotors helped dissipate those gases and get proper contact.

Fast fwd near 60 years like now.
Brake pads don't produce those gases anymore, so one would think removing heat dissipation material (metal) from a unit would go against cooling the brake system slower which it does.

Ever seen F1 carbon brakes with holes in them or Nascar?
Heat needs to dissipate into the metal, the more metal the more heat it can absorb (that's the theory).

The only improvement on brake disks has been the vented disk over solid to improve air flow in the middle.

Discloser;; yes the slots on that specific bike will reduce warping but increase cracking(due to stress)
I am not a brake expert but the math just add up to me,
Knowing that, ask EBC Brakes expert why they sell swiss cheeses brakes rotors they wont be able to answer you, I just did
gonna start a thread on that, to see how many people I piss off lol Cheers ride safe.

RuZty
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Re: brake info (not to the faint of heart)

#2 Post by RuZty » Wed Aug 22, 2018 10:11 pm

Actually, a 5mm hole in a 5mm thick disc increases the surface area by double for each hole verses the circle that's removed. It also reduces mass, which reduces inertia and unsprung weight, which improves braking, turning, acceleration and wheel control. It's a balancing act, you need enough mass in the disc to absorb the heat of stopping the bike and enough surface area to shed that heat as quickly as possible. Carbon rotors need the heat to work and holes probably wouldn't help structurally either, so that's kind of an apples and oranges comparison.
A hundred 5mm holes in each front rotor takes about a third of a kilogram of rotating mass off the wheel. I'll take the holes thanks.
....and there's a good chance they help in the rain too...

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Zedixe13
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Re: brake info (not to the faint of heart)

#3 Post by Zedixe13 » Thu Aug 23, 2018 1:09 am

And I would add , iron disks that rust a more effective in dissipating heat than our nice and shiny stainless steel disks but you won't see them on bikes cause they
are ugly , wear rapidly and they rust . Honda tried iron disks in the 80's with some covers to hide them .

evan_calgary
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Re: brake info (not to the faint of heart)

#4 Post by evan_calgary » Thu Aug 23, 2018 11:57 am

RuZty wrote:Actually, a 5mm hole in a 5mm thick disc increases the surface area by double for each hole verses the circle that's removed. It also reduces mass, which reduces inertia and unsprung weight, which improves braking, turning, acceleration and wheel control. It's a balancing act, you need enough mass in the disc to absorb the heat of stopping the bike and enough surface area to shed that heat as quickly as possible. Carbon rotors need the heat to work and holes probably wouldn't help structurally either, so that's kind of an apples and oranges comparison.
A hundred 5mm holes in each front rotor takes about a third of a kilogram of rotating mass off the wheel. I'll take the holes thanks.
....and there's a good chance they help in the rain too...
Bubble burst! This is all true... Math checks out and carbon brakes are scary when cold...

maybe time to /rant relics?

Hooligan
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Location: Calgary, Alberta

Re: brake info (not to the faint of heart)

#5 Post by Hooligan » Thu Aug 23, 2018 8:10 pm

addicted to relics wrote:ok I will get info out there that most don't know

its a copy from another thread

Not a lot of people know this but the reasoning of drilled / slotted rotors and why it looks cool and racy, it Is a fucking bummer, am about to crush your world down so bad am so sorry.

The pads from the 50's and 60's were new and bad technology, when heated, they created gases between the pads and rotors, not ideal when you want to brake to have a pocket of gas between your pads and rotors, hence the drilled and slotted rotors helped dissipate those gases and get proper contact.

Fast fwd near 60 years like now.
Brake pads don't produce those gases anymore, so one would think removing heat dissipation material (metal) from a unit would go against cooling the brake system slower which it does.

Ever seen F1 carbon brakes with holes in them or Nascar?
Heat needs to dissipate into the metal, the more metal the more heat it can absorb (that's the theory).

The only improvement on brake disks has been the vented disk over solid to improve air flow in the middle.

Discloser;; yes the slots on that specific bike will reduce warping but increase cracking(due to stress)
I am not a brake expert but the math just add up to me,
Knowing that, ask EBC Brakes expert why they sell swiss cheeses brakes rotors they wont be able to answer you, I just did
gonna start a thread on that, to see how many people I piss off lol Cheers ride safe.
Whoever wrote this is an idiot. :smt021

Vented disks were tried on bikes. My FZ750 has some. They didn't last long at all, probably because they were way too heavy and didn't work as intended. Brake disks have slots and holes in them for increased surface area and cooling as well as sweeping the pad surface of crap.
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

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OldTZracer
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Re: brake info (not to the faint of heart)

#6 Post by OldTZracer » Thu Aug 23, 2018 11:59 pm

Somebody needs to spend $28 & order the SAE paper on cross-drilling rotors:

The Effect of Rotor Crossdrilling on Brake Performance - 2006-01-0691
https://www.sae.org/publications/techni ... 06-01-0691" onclick="window.open(this.href);return false;
"...its a 2-stroke ya twit - Its supposed to smoke..."

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