single side brake??
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Join Date: Jan 2011
Location: Southeast Michigan 15 Minutes East Of Hell
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Physics dictates that the 13" rotor will exert more stopping power than a smaller diameter rotor by the means of "increased leverage" on the point of axis ... think about it .... spin a wheel and try to stop it by grabbing the wheel near the axle area or further out near the tire ... and as far a a caliper "breaking in" ... I've never heard, or seen, or encountered anything regarding this ... I've been an ASE mechanic ( now retired ) for more years than I care to remember ... It just doesn't make any sense ... hydraulic forces don't become greater or more effective as time/miles go by.
#13
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You will only take advantage of a dual disk setup if you are braking at very high speed. The additional disk will spread the braking heat and avoid the brake fluid boiling in the caliper causing brake fade..
I have single 11.5" rotor with a 4 piston on my softail and it will lock the front causing it to bounce if i squeeze hard enough at under 80MPH... This is more than enough for "normal" riding conditions.. I would notice dual disk if I was trying to panic stop at 115MPH but how often does that happen?
Dual disk is way overrated by people that don't even use it IMO....
Single disk is a performance advantage because of less rotating mass, unless you are racing...
So, single disk looks better, it performs better at a reasonable speed, leave dual disk for the high speed race bikes..
I removed the right disk from my FXRS and it looks better, lost weight (rotating mass) , and performs the same at normal speed..
Been riding over 30 years and tried it all, dual disk is way overrated IMO...
Added to the irony of this, how much brake do you really need to exceed the contact patch of a skinny 21" front tire? Seroiusly, I have since upgraded the front tire on my bike to a 18 X 130 tire and my single disk will lock it any time I want...
For cruising (not racing) ,Dual disk is a psychological advantage at best ...
#16
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At a most simplistic level the answer is Yes, you are right.
At a more detailed level (and assuming the HD ABS system does exactly what it should do as I am sure many will now chime in and take this off on a tangent) it is key to understand that ABS is actually concerned with traction control.
Why is this statement relevant? This is easiest described by considering extremes. Clearly if you were riding on ice then it takes the smallest of braking efforts to trigger the ABS. You could therefore use your argument to justify putting bicycle brakes on a bagger!
As we increase the level of traction to a point where we are braking on Tarmac that is firm, gravel free and no potholes it is possible that you will not trigger the AbS.
Assuming for now that, even in these ideal conditions, you can trigger ABS it will be as a result of you having to pull twice as hard on the brake lever (assuming a linear relationship between lever force and brake hydraulic pressure).
Given that the system pressure is now twice the pressure of the dual rotor system I would not want to hazard a guess at how well the ABS modulation will work. Personally, from my experience of designing closed loop hydraulic control systems, that is a risk I would not even begin to contemplate, especially as the time I am going to really test it in anger I probably won't get a second chance if it doesn't work!
#17
#18
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That is an excellent observation / question.
At a most simplistic level the answer is Yes, you are right.
At a more detailed level (and assuming the HD ABS system does exactly what it should do as I am sure many will now chime in and take this off on a tangent) it is key to understand that ABS is actually concerned with traction control.
Why is this statement relevant? This is easiest described by considering extremes. Clearly if you were riding on ice then it takes the smallest of braking efforts to trigger the ABS. You could therefore use your argument to justify putting bicycle brakes on a bagger!
As we increase the level of traction to a point where we are braking on Tarmac that is firm, gravel free and no potholes it is possible that you will not trigger the AbS.
Assuming for now that, even in these ideal conditions, you can trigger ABS it will be as a result of you having to pull twice as hard on the brake lever (assuming a linear relationship between lever force and brake hydraulic pressure).
Given that the system pressure is now twice the pressure of the dual rotor system I would not want to hazard a guess at how well the ABS modulation will work. Personally, from my experience of designing closed loop hydraulic control systems, that is a risk I would not even begin to contemplate, especially as the time I am going to really test it in anger I probably won't get a second chance if it doesn't work!
At a most simplistic level the answer is Yes, you are right.
At a more detailed level (and assuming the HD ABS system does exactly what it should do as I am sure many will now chime in and take this off on a tangent) it is key to understand that ABS is actually concerned with traction control.
Why is this statement relevant? This is easiest described by considering extremes. Clearly if you were riding on ice then it takes the smallest of braking efforts to trigger the ABS. You could therefore use your argument to justify putting bicycle brakes on a bagger!
As we increase the level of traction to a point where we are braking on Tarmac that is firm, gravel free and no potholes it is possible that you will not trigger the AbS.
Assuming for now that, even in these ideal conditions, you can trigger ABS it will be as a result of you having to pull twice as hard on the brake lever (assuming a linear relationship between lever force and brake hydraulic pressure).
Given that the system pressure is now twice the pressure of the dual rotor system I would not want to hazard a guess at how well the ABS modulation will work. Personally, from my experience of designing closed loop hydraulic control systems, that is a risk I would not even begin to contemplate, especially as the time I am going to really test it in anger I probably won't get a second chance if it doesn't work!
I guess the point is, single disk will still stop you if you have the skills to use the system but duals are better for the average rider unfamiliar with the proper pressure applied to the brake lever...
Or, perhaps I missed the point...
ABS is a dummy system made to override a panic stop by a poor operator.
A skilled pilot has no need for ABS and can regulate brake pressure by feedback from the road...
I can see where dual disks will result in more accurate braking as well as spreading the heat to avoid brake fade. These things really don't matter unless you are braking at speeds well above the norm...
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