Yes; he already mentioned that. They're great for repeated braking. But, you get guys wanting to buy them for their daily drivers, when they don't go more than 30 miles an hour and put on 5 miles a day, hardly a situation needing a big brake kit.
Brake Rotor Friction Characteristics?
- Thread starter meep
- Start date
- Status
Originally Posted By: Garak
Yes; he already mentioned that. They're great for repeated braking. But, you get guys wanting to buy them for their daily drivers, when they don't go more than 30 miles an hour and put on 5 miles a day, hardly a situation needing a big brake kit.
:lol: So true! Even my track cars don't need a BBK, good set of pads, good fluid and most importantly, good tires. And I can usually out brake most guys with those BBK's installed.
It's the tires that stop the vehicle, not the brakes.
Yes; he already mentioned that. They're great for repeated braking. But, you get guys wanting to buy them for their daily drivers, when they don't go more than 30 miles an hour and put on 5 miles a day, hardly a situation needing a big brake kit.
:lol: So true! Even my track cars don't need a BBK, good set of pads, good fluid and most importantly, good tires. And I can usually out brake most guys with those BBK's installed.
It's the tires that stop the vehicle, not the brakes.
Last edited:
Originally Posted By: dareo
All brake rotors are made in China out who knows what. I mean have you actually seen one that isn't Chinese anymore?
Absolutely. The rotors on my BMW are made in Germany, the rotors on my Civic are made in Japan.
And to the OP, warped rotors are usually caused by improperly torquing of wheel nuts, that is if they are actually warped, and not uneven pad deposits.
Racing in Chump, we do 7-12 hour races. I have never seen a warped rotor at the track, it is not caused by heat.
All brake rotors are made in China out who knows what. I mean have you actually seen one that isn't Chinese anymore?
Absolutely. The rotors on my BMW are made in Germany, the rotors on my Civic are made in Japan.
And to the OP, warped rotors are usually caused by improperly torquing of wheel nuts, that is if they are actually warped, and not uneven pad deposits.
Racing in Chump, we do 7-12 hour races. I have never seen a warped rotor at the track, it is not caused by heat.
Last edited:
Originally Posted By: Garak
Yes; he already mentioned that. They're great for repeated braking. But, you get guys wanting to buy them for their daily drivers, when they don't go more than 30 miles an hour and put on 5 miles a day, hardly a situation needing a big brake kit.
They can actually be more economical in the long run when it comes to consumables, too. Since you are straining the system less and can run thicker + larger pads, you replace parts less often. The cost-per-mile is much less.
Yes; he already mentioned that. They're great for repeated braking. But, you get guys wanting to buy them for their daily drivers, when they don't go more than 30 miles an hour and put on 5 miles a day, hardly a situation needing a big brake kit.
They can actually be more economical in the long run when it comes to consumables, too. Since you are straining the system less and can run thicker + larger pads, you replace parts less often. The cost-per-mile is much less.
All right I have a couple of questions... Would steel on steel brake pads rated EE slow down and stop a car as effectively as semi metallic brake pad pads rated FF?? Would a car with steel brake pads stop as well as ceramic brake pads rated GG?? All of this given that the tires are well up to the task and perform very well. Given that there is a much higher coefficient of friction of semi metallic brake pads and ceramics over steel brake pads. Is it that steel brake pads rated EE are just fine for short term daily use? It is just that these EE rated brake pads would have to be changed much more often due to wearing much quicker. So, that means that higher rated brake pads only gave the obvious advantage of longevity and maintaining performance in repeated high heat usage?? And that the higher coefficient of friction actually means nothing in terms of turning forward motion/kinetic energy into heat more effectively and efficiently than lower coefficient of friction brake pads. Again, given that the tires are performing well in terms of stopping ability. Then I wonder what is the point of having a coefficient of friction rating for "cold braking" the first letter in the rating system?? I am just curious as to these answers. I want to understand the how that all works out.
The brake feel changes when you go to higher friction coefficient brake pads as you need less pedal pressure for the same braking effort. But the ratings on the brake pads mean more than just friction coefficient, they also adress fade.
Different compounds react differently to temperature. Get a racing pad and it quite normal that the first brake application of the day IS NOT capable of locking the wheels.
The reason why there's a low temp and high temp rating: light use and harder use.
There's much more to brakes than just the friction coefficient or fade though, and it's also the other pad peculiarities that make or break a good braking system:
- Initial bite
- Bedding in quality and speed
- Compressiility
- Heat conductivity
- wear rate
- Consistency in feel (wet/dry/hot/cold/rust on discs or clean)
- upfront price
to name a few...
Different compounds react differently to temperature. Get a racing pad and it quite normal that the first brake application of the day IS NOT capable of locking the wheels.
The reason why there's a low temp and high temp rating: light use and harder use.
There's much more to brakes than just the friction coefficient or fade though, and it's also the other pad peculiarities that make or break a good braking system:
- Initial bite
- Bedding in quality and speed
- Compressiility
- Heat conductivity
- wear rate
- Consistency in feel (wet/dry/hot/cold/rust on discs or clean)
- upfront price
to name a few...
I appreciate your response here. Yeah I understood that it more than just coefficient of friction that matters in terms of performance. The first part of your answer makes a lot of sense to me in reference to my question. Of course the rest of your answer was very good too. Thank you again. I enjoy learning about how different things work and why.
Originally Posted By: dparm
That is absolutely not true. BMW specs very thick rotors for its cars that will last a long time. The heavier rotors will also help with the heat for those harder stops at autobahn speeds. A possible third reason is that due to the no-cost maintenance, BMW wants the rotors to last longer than the free maintenance period so they don't have to shell out for new ones on every car they sell.
BMW does not recommend turning rotors and no dealer will do it.
Go on any of the BMW websites and you will hear everyone talking about how long their OEM rotors last. My M3's lasted over 60k, and would've gone longer had it not been for track use. Tons of guys on M3post are getting two or three sets of pads per set of rotors.
I don't know what the metallurgy is for the rotors, however.
Perhaps this is true on the M models, but every E46/E60/E90 vehicle that has been in for brakes (for the record, I do not work on many) had front rotors that measured well below the minimum thickness. The rear rotors were a slightly different story, but I still suggest new rotors with pad replacement as a precaution against noise/vibration complaints.
That is absolutely not true. BMW specs very thick rotors for its cars that will last a long time. The heavier rotors will also help with the heat for those harder stops at autobahn speeds. A possible third reason is that due to the no-cost maintenance, BMW wants the rotors to last longer than the free maintenance period so they don't have to shell out for new ones on every car they sell.
BMW does not recommend turning rotors and no dealer will do it.
Go on any of the BMW websites and you will hear everyone talking about how long their OEM rotors last. My M3's lasted over 60k, and would've gone longer had it not been for track use. Tons of guys on M3post are getting two or three sets of pads per set of rotors.
I don't know what the metallurgy is for the rotors, however.
Perhaps this is true on the M models, but every E46/E60/E90 vehicle that has been in for brakes (for the record, I do not work on many) had front rotors that measured well below the minimum thickness. The rear rotors were a slightly different story, but I still suggest new rotors with pad replacement as a precaution against noise/vibration complaints.
MolaKule
Staff member
Here is an article that may be of interest:
http://www.sciencedirect.com/science/article/pii/S0043164809000611
http://www.sciencedirect.com/science/article/pii/S0043164809000611
- Status