what are floating rotors?
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Road Captain
Joined: Jan 2006
Posts: 521
Likes: 0
From: Greenwood, IN
what are floating rotors?
can someone please tell me floating rotors are? i am assuming that the stock rotors are not floating huh? i have a 2000 road king classic. i am getting ready to install the chrome fork lowers and was wondering if i should put different rotors on it at the same time. also how much does it cost to go with the floating rotors? and what are the advantages of the floating rotors, sorry for all of the questions just trying to educate my self
Elite HDF Member
Joined: Feb 2006
Posts: 4,519
Likes: 5
From: Slidell, LA
RE: what are floating rotors?
Got this a while back. Don't remember who wrote it though. Pretty good stuff.
Floaters are definitely a much improved method for attaching the rotor to the wheel and should in this day and time be standard equipment on a heavy weight Harley. Hopefully none of us are riding our touring bikes in a manner that requires heavy performance braking like a sport bike, but consider summer temperatures and riding in the twisties two up and there is mucho heat built up in the direct bolt on OEM HD rotors. Not good!
All metals "grow" when heated. The diameter of cast iron brake discs can increase as much as 2 or 3mm at elevated braking temperatures. When the disc is radially restrained from growing (as in all one-piece rotors in the stock Harley bolt on configuartion) the friction plates (rotors) are forced into a cone shape as temperature increases, adversely effecting both temperature and pressure distribution within the pads and the feel of the break pedal or brake lever.
Then add in the fact that conventional brake rotors donât run absolutely true. They all wiggle a little bit. No matter how careful you are about truing them up and and any bearing looseness, rotor wear, manufacturing tolerances of the hub, rotor, and rotor adaptor all add up. This can cause a feeling of brakes pulsing and decreased peformance.
This is where dynamically mounted (floating rivet attachement) rotors come in. When you dynamically mount a brake rotor you allow a small amount of movement axially (side to side). When a brake rotor is spinning it can contain large amounts of stored energy. Under Newton's first law of motion he states that any body will continue in its state of motion (still or traveling) until outside forces change it. What this means is once the rotor is spinning it finds where it needs to be and stays there. That is the beauty of the floating rotor design.
IMHO putting floating rotors on a HD touring machine is a super inexpensive peformance upgrade for one of the most important safety features on a motorcyle. Maybe this should be a new rumor for 2007 HD. Standard equipment ALL bikes have floating rotors.
Floaters are definitely a much improved method for attaching the rotor to the wheel and should in this day and time be standard equipment on a heavy weight Harley. Hopefully none of us are riding our touring bikes in a manner that requires heavy performance braking like a sport bike, but consider summer temperatures and riding in the twisties two up and there is mucho heat built up in the direct bolt on OEM HD rotors. Not good!
All metals "grow" when heated. The diameter of cast iron brake discs can increase as much as 2 or 3mm at elevated braking temperatures. When the disc is radially restrained from growing (as in all one-piece rotors in the stock Harley bolt on configuartion) the friction plates (rotors) are forced into a cone shape as temperature increases, adversely effecting both temperature and pressure distribution within the pads and the feel of the break pedal or brake lever.
Then add in the fact that conventional brake rotors donât run absolutely true. They all wiggle a little bit. No matter how careful you are about truing them up and and any bearing looseness, rotor wear, manufacturing tolerances of the hub, rotor, and rotor adaptor all add up. This can cause a feeling of brakes pulsing and decreased peformance.
This is where dynamically mounted (floating rivet attachement) rotors come in. When you dynamically mount a brake rotor you allow a small amount of movement axially (side to side). When a brake rotor is spinning it can contain large amounts of stored energy. Under Newton's first law of motion he states that any body will continue in its state of motion (still or traveling) until outside forces change it. What this means is once the rotor is spinning it finds where it needs to be and stays there. That is the beauty of the floating rotor design.
IMHO putting floating rotors on a HD touring machine is a super inexpensive peformance upgrade for one of the most important safety features on a motorcyle. Maybe this should be a new rumor for 2007 HD. Standard equipment ALL bikes have floating rotors.
Elite HDF Member
Joined: May 2006
Posts: 3,927
Likes: 5
From: Midwest
RE: what are floating rotors?
In english... :^)
Your stock rotors are one solid piece of metal that bolts to the hub. They may or may not be exactly parallel with your brake pads depending on whether your rotor and brake caliper are exactly aligned, and when you hit the brakes your pad may not be completely flat against the rotor face.
When things are right, your rotor will be exactly aligned between your pads, like this: ] | [
Usually, though, your rotor will be a little off compared to your pads, giving you something like this: ] / [
Since the both pads and the rotor are bolted into position, your pads don't make contact over their entire face, just on the edges when you apply pressure. ]/[
Floating rotors are 2 pieces of metal. When bolted tightly to your hub there will still be some "play" in the outer part that contacts the brake pads which will allow the face to "float", or compensate for small differences in alignment, and allow you to still have 100% contact with the brake pads even if the hub and caliper aren't perfectly aligned.
Whether the upgrade is worth it is up to you.
Hope that helps.
Your stock rotors are one solid piece of metal that bolts to the hub. They may or may not be exactly parallel with your brake pads depending on whether your rotor and brake caliper are exactly aligned, and when you hit the brakes your pad may not be completely flat against the rotor face.
When things are right, your rotor will be exactly aligned between your pads, like this: ] | [
Usually, though, your rotor will be a little off compared to your pads, giving you something like this: ] / [
Since the both pads and the rotor are bolted into position, your pads don't make contact over their entire face, just on the edges when you apply pressure. ]/[
Floating rotors are 2 pieces of metal. When bolted tightly to your hub there will still be some "play" in the outer part that contacts the brake pads which will allow the face to "float", or compensate for small differences in alignment, and allow you to still have 100% contact with the brake pads even if the hub and caliper aren't perfectly aligned.
Whether the upgrade is worth it is up to you.
Hope that helps.
Road Master
Joined: Nov 2006
Posts: 1,227
Likes: 3
From: Central Illinois
RE: what are floating rotors?
Brakes are designed with one of two floating rotors or floating calipers. Floating calipers are mounted on pinsand are not directly attached to the fork leg. When the brake is released it allows the caliper to center on the brake rotor and the piston to retract with minimal drag. If the caliper is solid mounted to the fork leg the rotor has pins that attach between the carrier (which is bolted directy to the wheel) and the rotor. These pins allow the rotor to move independently from the carrier and reduce drag.
The MOCO stock caliper on FL's are solid mounted as are the rotors. the rotor is designed with the swept patterns taht allow the rotors to float. This is not very affective, as you can tell by the "swishing" noise you hear while riding. all that noise is the rotors riding on the pads, reducing pad life. Floating rotors reduce heat and extend pad life. Harley's floating rotors are not true floating rotors. The "pins" do not allow the rotor to move independent of the carrier enough to work effectively. Find a good true floating rotor and it will reduce noise and extend pad life. Besides the appearence.
The MOCO stock caliper on FL's are solid mounted as are the rotors. the rotor is designed with the swept patterns taht allow the rotors to float. This is not very affective, as you can tell by the "swishing" noise you hear while riding. all that noise is the rotors riding on the pads, reducing pad life. Floating rotors reduce heat and extend pad life. Harley's floating rotors are not true floating rotors. The "pins" do not allow the rotor to move independent of the carrier enough to work effectively. Find a good true floating rotor and it will reduce noise and extend pad life. Besides the appearence.
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Tourer
Joined: May 2006
Posts: 477
Likes: 1
From: Ventura County, CA
RE: what are floating rotors?
ORIGINAL: jd_underdog
ok well that does tell me what they are. how expensive is it to put them on a roadking? what all parts would be needed
ok well that does tell me what they are. how expensive is it to put them on a roadking? what all parts would be needed
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