Nice video. More can be discussed but good overview. Things to go into for the future: why do rotors crack and how to prevent cracking. Proper fastening of 2piece rotors wire tie vs loctite. What customer/use needs a certain type of rotor (street, dual duty, track).
I remember reading an interview with the first guy who ever drilled holes in a Kawasaki brake rotor (I believe it was an H2 750 2-stroke street race bike). He said that 100% of the reason they did it was to save weight. Disc brakes were brand new to motorcycles at this time, and as it turns out they were monstrously over-built. My 400 triple from 1974 makes just 42hp, but the front rotor is almost the same dimensions (diameter, thickness, WEIGHT) as the rear discs on my NC. If anything, the 400's rotor is bigger. The rear drum on that bike is sized about halfway between the drums on my Insight and my Dakota. Huge. After a really hard down-hill run, the brakes are no hotter than if you left the bike sitting in the sun for 15 minutes. My front rotor on the Kawasaki was stock from 1974, but I still had to get it turned down several milimeters just to cram a modern Ninja caliper over it. A modern 200hp literbike has less thermal mass than my little 2-stroke beginner bike. You could drill those war hammers without a care in the world. Circumstances today are different, and the story about what the holes are for got changed.
I think that was literally the most informative talk on brake rotors I've seen. Thank you, confirmed some things I already knew and added a little bit of knowledge to my already stuffed brain.
Informative video, like it. A video on calipers would be nice. Six pistons vs four pistons vs stock and brake master cylinder sizing for bigger calipers.
We’ve done a few other videos on other parts of the brake system - check out our channel. A well chosen caliper shouldn’t require a master cylinder change.
Thanks for the explanation on warped rotors! So if warped rotors are caused by sticky material on the rotor surface, which in turn causes uneven braking surface, will rotor resurfacing solve the problem (given there is more than enough rotor thickness left)?
Am I just old? I remember two piece rotors requiring safety wire. If that is still done, I haven't seen it discussed much. I'm slowly turning my daily driver ND into a track capable toy. If I was to understand correctly, two piece rotors are subject to potentially loosening fasteners is it still a good practice to overdo it and safety wire what you can for peace of mind?
Some rotors use mechanically locking fasteners to avoid the need for safety wire and make them much easier to install. The downside is that the fasteners aren’t reusable.
Single stop distance is basically a function of traction and proportioning. Rotor selection isn’t really a factor. The bigger systems come into play when you’re dealing with the heat from repeated hard braking events, like track driving. We’ve done a few different videos on overall braking system design - you can check them out on our channel.
As mentioned in the video, rear rotors wouldn't get much benefit from being veined as they don't do as much work. Would the only benefit possible be unsprung weight reduction with a two-piece rotor that has no veins?
I think that goes back to the one side is heated more than the other. I've turned plenty of rotors over the years and it always seems to be the inside edge that needs a little extra.
4k looks great, guys!
Nice video. More can be discussed but good overview. Things to go into for the future: why do rotors crack and how to prevent cracking. Proper fastening of 2piece rotors wire tie vs loctite. What customer/use needs a certain type of rotor (street, dual duty, track).
I remember reading an interview with the first guy who ever drilled holes in a Kawasaki brake rotor (I believe it was an H2 750 2-stroke street race bike). He said that 100% of the reason they did it was to save weight. Disc brakes were brand new to motorcycles at this time, and as it turns out they were monstrously over-built. My 400 triple from 1974 makes just 42hp, but the front rotor is almost the same dimensions (diameter, thickness, WEIGHT) as the rear discs on my NC. If anything, the 400's rotor is bigger. The rear drum on that bike is sized about halfway between the drums on my Insight and my Dakota. Huge. After a really hard down-hill run, the brakes are no hotter than if you left the bike sitting in the sun for 15 minutes. My front rotor on the Kawasaki was stock from 1974, but I still had to get it turned down several milimeters just to cram a modern Ninja caliper over it. A modern 200hp literbike has less thermal mass than my little 2-stroke beginner bike. You could drill those war hammers without a care in the world. Circumstances today are different, and the story about what the holes are for got changed.
The founder of FM used an aluminum rear rotor on his race motorcycle. Don't try this on a car!
I think that was literally the most informative talk on brake rotors I've seen. Thank you, confirmed some things I already knew and added a little bit of knowledge to my already stuffed brain.
Glad it was helpful!
Thanks for another great video!
Glad you enjoyed it!
Thanks Keith! I learned a lot from this session.
Glad we could help!
Informative video, like it. A video on calipers would be nice. Six pistons vs four pistons vs stock and brake master cylinder sizing for bigger calipers.
We’ve done a few other videos on other parts of the brake system - check out our channel. A well chosen caliper shouldn’t require a master cylinder change.
Can you touch base a little more on free floating rotors? Are most good two-piece rotors floating?
Thanks for the explanation on warped rotors! So if warped rotors are caused by sticky material on the rotor surface, which in turn causes uneven braking surface, will rotor resurfacing solve the problem (given there is more than enough rotor thickness left)?
As long as your pads have even wear, and you have enough surface on the rotor to turn them, that should definitely help.
Am I just old? I remember two piece rotors requiring safety wire. If that is still done, I haven't seen it discussed much.
I'm slowly turning my daily driver ND into a track capable toy.
If I was to understand correctly, two piece rotors are subject to potentially loosening fasteners is it still a good practice to overdo it and safety wire what you can for peace of mind?
Some rotors use mechanically locking fasteners to avoid the need for safety wire and make them much easier to install. The downside is that the fasteners aren’t reusable.
would love to see a video 60-0 with each level of upgrades on the same car with big sticky tyres so we could quantify the upgrade path for road use?
Single stop distance is basically a function of traction and proportioning. Rotor selection isn’t really a factor.
The bigger systems come into play when you’re dealing with the heat from repeated hard braking events, like track driving. We’ve done a few different videos on overall braking system design - you can check them out on our channel.
As mentioned in the video, rear rotors wouldn't get much benefit from being veined as they don't do as much work. Would the only benefit possible be unsprung weight reduction with a two-piece rotor that has no veins?
Weight reduction and heat dissipation.
Warped rotors absolutely do happen though, seen it myself. The entire rotor wobbling, including un-worn surfaces not touched by the pad.
I think that goes back to the one side is heated more than the other. I've turned plenty of rotors over the years and it always seems to be the inside edge that needs a little extra.
Very interesting, and good luck getting this sort of straight talk on what you need and don't on a street car on a forum.