Real world difference in stopping? Single vs dual
#131
Chonk: I cited the mag article on the riding class in California. How the instructor determines the g forces involved I do not know.
I read four or more motorcycle publications per month and have a library of hard back books on motorcycling. I have been riding for 60 years and around a half million miles and have never went down.
I practice two maneuvers each month of riding. One is the emergency stop. You quickly pull the clutch and just start on both brakes lightly. Feed in the front brake and increase the pressure until the forks are bottomed out which is the point that the most weight of the bike is pressing on the contact patch. Only slightly add pressure to the rear brake.
The other is object avoidance. Going down the road in the center of your lane make an abrupt countersteer one direction then immediately countersteer the other way at a spot you picked out ahead of you such as a pot hole. The idea is to avoid the object not leave the lane and return to to the same line as before the maneuver.
Just how do you practice braking?
Tech note: HD's do have a accelerometer sensor and an incline sensor. The ecm uses the data from them with the speed sensor, time and a couple of algorithms to decide that you no longer need to have the turn signals on. The incline sensor is also used for the ECM to decide it better shut the engine off when your bike is on it's side from not braking correctly.
I read four or more motorcycle publications per month and have a library of hard back books on motorcycling. I have been riding for 60 years and around a half million miles and have never went down.
I practice two maneuvers each month of riding. One is the emergency stop. You quickly pull the clutch and just start on both brakes lightly. Feed in the front brake and increase the pressure until the forks are bottomed out which is the point that the most weight of the bike is pressing on the contact patch. Only slightly add pressure to the rear brake.
The other is object avoidance. Going down the road in the center of your lane make an abrupt countersteer one direction then immediately countersteer the other way at a spot you picked out ahead of you such as a pot hole. The idea is to avoid the object not leave the lane and return to to the same line as before the maneuver.
Just how do you practice braking?
Tech note: HD's do have a accelerometer sensor and an incline sensor. The ecm uses the data from them with the speed sensor, time and a couple of algorithms to decide that you no longer need to have the turn signals on. The incline sensor is also used for the ECM to decide it better shut the engine off when your bike is on it's side from not braking correctly.
Last edited by lh4x4; 04-05-2016 at 07:54 PM.
#132
#133
This confuses me. I know that a good rider in perfect conditions can potentially out stop ABS by threshold braking, but where do G's come into the picture? I didn't think Harley's have accelerometers, so how are G's measured? My understanding of ABS is there is a rotation sensor that compares the speed of the wheel with speed when brakes are applied and the rotation of the other wheel and senses a rapid deceleration (lockup), releasing the caliper until the wheel starts spinning again, pumps up to reapply braking, and repeat many times a second.
Where do measuring G's come into the picture, and why would it care how many G's are being experienced? (I guess maybe to prevent you from flying off the bike, but I doubt the contact patch of both tires can produce enough deceleration to do that, and if so, maybe you shouldn't be riding...
Where do measuring G's come into the picture, and why would it care how many G's are being experienced? (I guess maybe to prevent you from flying off the bike, but I doubt the contact patch of both tires can produce enough deceleration to do that, and if so, maybe you shouldn't be riding...
The comment about Gs comes from years of reading about ABS and I cannot find where it was introduced. I can recall it being stated in a magazine report but can't find it.
Now if I go back and think about how ABS works yes it is about difference in wheel rotation.
I'm sorry but still don't agree with the heavy effort on the lever being important. I prefer to have feel at the lever. Having a heavier pull on the lever still makes no sense to me.
I was classically trained in auto racing where brake pedal modulation is key to stopping quickly. This is also why I have been following ABS so much over the years because ABS precludes pedal/lever modulation.
I actually don't like ABS because I still feel that in the vast majority of conditions I can do just fine. I probably don't practice braking enough but feel that I ride aggressively enough to have a very good sense of braking capability.
I tried to stay on OP's topic but fell into the overall braking issue.
There are a lot of variables which I believe were well stated.
My experience over 5 Harleys I've owned (just received my Low Rider S) tells me that stock H-D single front disc brakes are very hard to get to the lockup point.
Harley brakes suck. My new S has very spongy brakes which is why it is in the shop getting SS braided lines and EBC HH sintered pads as well as a full floating rear rotor.
If I ever find the reference about max Gs on ABS I'll be sure to post it but I will yield to the comment about wheel rotation differential because I do know that to be true.
I put a high priority on braking so that is where most of my modification dollars are going on the bike right now. Next is ordering a set of Ohlins rear shocks and figure out what to do about the front end.
Thanks.
Chonk
Last edited by Chonk; 04-08-2016 at 09:59 AM.
#134
#137
C'mon Chonk, you've got "a ways" to go, but may be you just breathed some new life into this thread
AKFXD...you could put out a little more effort yourself
cvaria...content with being first of the last placers?
Damn...I just tied for Third
(btw, "triple smilie" again)
AKFXD...you could put out a little more effort yourself
cvaria...content with being first of the last placers?
Damn...I just tied for Third
(btw, "triple smilie" again)
#138
With all the expert replies here I lost track of who said what so pardon me If I'm parroting what someone else said. To me dual disc's are about being able to slow down when you need to. I'm not talking contact patch or stopping distance. I'm talking about coming into a corner hot, too fast to make it around in one piece.
If you've ever been out hot rodding with your buds, fast as you can go in the straights, then jamming on the stoppers as late as you can in the corner only to find the brakes don't work as you are pulling as hard as you can on the lever you'll wish you had dual disc's. More surface area = cooler running = better stopping power.
Now, if you're not an adrenalin junkie or highly competitive and never experienced brake fade, you may not need dual disc's. Unless you want to look like an adrenalin junkie.
If you've ever been out hot rodding with your buds, fast as you can go in the straights, then jamming on the stoppers as late as you can in the corner only to find the brakes don't work as you are pulling as hard as you can on the lever you'll wish you had dual disc's. More surface area = cooler running = better stopping power.
Now, if you're not an adrenalin junkie or highly competitive and never experienced brake fade, you may not need dual disc's. Unless you want to look like an adrenalin junkie.
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Chonk (04-13-2016)
#139
With all the expert replies here I lost track of who said what so pardon me If I'm parroting what someone else said. To me dual disc's are about being able to slow down when you need to. I'm not talking contact patch or stopping distance. I'm talking about coming into a corner hot, too fast to make it around in one piece.
If you've ever been out hot rodding with your buds, fast as you can go in the straights, then jamming on the stoppers as late as you can in the corner only to find the brakes don't work as you are pulling as hard as you can on the lever you'll wish you had dual disc's. More surface area = cooler running = better stopping power.
Now, if you're not an adrenalin junkie or highly competitive and never experienced brake fade, you may not need dual disc's. Unless you want to look like an adrenalin junkie.
If you've ever been out hot rodding with your buds, fast as you can go in the straights, then jamming on the stoppers as late as you can in the corner only to find the brakes don't work as you are pulling as hard as you can on the lever you'll wish you had dual disc's. More surface area = cooler running = better stopping power.
Now, if you're not an adrenalin junkie or highly competitive and never experienced brake fade, you may not need dual disc's. Unless you want to look like an adrenalin junkie.
Roger
#140
I'm adding semi-sintered pad and SS braided brake lines to see if I can get rid of the spongy lever pull and introduce some feel.
Supposedly the combination of organic and sintered metal will give good brake feel.
Also, from my research the OEM brake pads are sintered metal. These take a special break in which includes a dramatic heat cycle (there I go speaking from memory again...).
Only ridden my FXDL-S 7 miles before taking it back to the shop for brake upgrades and other tweaks but definitely noticed sponginess that should not have been there.
Last time I felt that sponginess was on my Switchback which ended up with a front master cylinder recall.
Chonk