| Author | Message | ||
     Nik |
Hell we'd probably be riding in model T's still. Normal people wouldn't dare operate one of them newfangled horseless carriages! | ||
| Slaughter |
WOW - designing a hypercomplicated system that by rights is rarely used and then when it IS used, isn't used heavily... unless you're off-roading. This makes my feeble brain really HURT | ||
| Nik |
Except the purpose of ZTL isn't to improve braking, its to allow for a lighter rotating assembly. I don't really see how its complicated either. It's just inside out. | ||
| Froggy |
Move the brake off the swingarm onto the front pulley, mount the rear pulley to the rim, make the swing arm single sided, redesign your wheel and make it lighter and volla, you knocked off a ton of unsprung weight  | ||
| Jaimec |
Only from what I've seen, bikes with single-sided swingarms tend to have even MORE unsprung weight than bikes with dual-sided swingarms. It's because the single arm has to be that much more beefy to resist flexing and twisting forces. Same reasons convertibles often weigh more than their hardtop equivalents. | ||
| Blake |
Rim mounted sprocket not same as rim mounted brake. Brake rotor and carrier are nice and flat planar in same plane as applied load from brake pads/caliper. Sprocket will have loading not perfectly in-plane with carrier. So there will be significant bending in sprocket's carrier. Not good. Flex make for fatigue and cracking. | ||
| Jaimec |
Blake, that was my point originally, but perhaps I didn't express myself clearly. In order to combat the flex you mentioned, the part would have to be built stronger and heavier which would eliminate the whole purpose of reducing unsprung weight. | ||
| Slaughter |
By complicated - I was referring to all the belt-and-suspenders braking systems being implied... I think for the rear? Maybe my problem is that I'm not taking the time to read through them all. Somehow, I think that Buell engineering has been down these paths once or twice and there's probably a reason that the rear brake is as "small" as it is. | ||
| Iamarchangel |
Slaughter: people who don't use the back brake think you need a bigger one until they learn to use the front brake. (Go to motogp and look at the size of Rossi's rear brake. Tiny.) Your earlier statement was probably best. Why have increased complexity and risk for a little used component? (I haven't used mine since I lowered the pegs. I can't even adjust the pedal low enough to reach it. So I've spent over a year wondering if I can cut the adjuster threads for more lowering or refab the pedal to have a lower tab.) (Message edited by iamarchangel on September 26, 2009) | ||
| Jaimec |
The rear brake is really only used to start the weight transfer from the rear of the bike to the front. Due to the Buell's light weight and short wheelbase (and this is true of nearly all modern sport bikes), once the front brake really starts biting down, there really isn't a whole lot of weight on the rear wheel at all. That being the case, the small rotor on the rear is really all that is necessary. On a longer wheelbased bike, there is less weight transfer so the rear brake has more impact on braking. Also, in poor traction conditions when you don't use the front brake as aggressively the rear brake becomes more useful in stopping the bike. In any event, the rear brake on the Buell is as big as it has to be and no bigger. | ||
| Blake |
The weight transfer myth is an old one. You can just as easily get the bike to gently transition into braking by judicious application of the front brake. It's just easier to be gentle using the rear brake. I've learned not to try to use the rear brake on the track, so certainly no need for it on the street unless as you say conditions are treacherous. Keep in mind that even on a wet road, a stoppie is possible. | ||
| Ourdee |
I use the rear brake to hold the bike in position at stop lights and for low speed figure eights. I just touch it when slowing from 70 to 5 mph. I use it above 70 in straight line running but not very hard. | ||
| Jaimec |
"Weight transfer MYTH???" So in effect, you're saying the rear brake DOESN'T cause the weight to transfer to the front wheel??? (Message edited by Jaimec on September 28, 2009) | ||
| Iamarchangel |
Any lowering of speed transfers the weight. Compression braking will transfer the weight, the suspension will react to it. The need to purposefully weight transfer, when you're not in the air, is probably the myth. I don't know. Like I said before, I don't use the rear brake at all and weight is transferred rather suddenly. It's probably like when people talk about cornering and get all hung up on reverse steering. That's just one aspect, there's a whole lot more to it than that one thing. | ||
| Ft_bstrd |
The weight transfer myth is an old one. I don't understand this statement either. Applying the rear brake causes not only the rider's weight to transfer forward but also the gas in the tank and the oil in the crank case. How could it not? | ||
| Iamarchangel |
http://www.motorcyclecruiser.com/streetsurvival/06 08_crup_effective_braking/index.html Pretty good discussion but makes it seem like it is a step by step process instead of basically all at once. Look at the time element. http://www.msgroup.org/forums/mtt/topic.asp?TOPIC_ ID=172 Way too much math but some people like that. Anyway, weight transfer is something that happens when you brake, as opposed to something you are trying to do while you brake at the same time. | ||
| Blake |
>>> you're saying the rear brake DOESN'T cause the weight to transfer to the front wheel??? No. The myth is that the rear brake more optimally performs the task. "Weight", to be technically accurate really isn't the major factor; the major factor increasing load on the front axle while decreasing load on the rear axle is inertia. | ||
| Jaimec |
But the simple fact of the matter is that two wheels braking is going to slow the bike a LOT faster than one wheel braking while the other freewheels. That's a fact. Motorcycles doing stoppies don't stop as quickly as motorcycles that keep both wheels planted on the ground for the same reason that motorcycles doing wheelies don't launch as fast as motorcycles that keep both wheels on the ground. The difference between not using the rear brake and using the rear brake COULD be the inches you need to avoid hitting the object you're trying to avoid in the first place. But, as in all things... it's your bike. Do what you want with it. As I tell the students I coach in the ERC: I don't feel a thing when your ass hits the ground. | ||
| Ft_bstrd |
Jamie, I would say that's true up to the point that the rear wheel loses contact patch or contact with the ground. At that point, it doesn't matter whether you are using the rear brake or not. In most riding situations, though, most aren't using the front brake with such "gusto" as to invoke a stoppie at every stop. | ||
| Blake |
"But the simple fact of the matter is that two wheels braking is going to slow the bike a LOT faster than one wheel braking while the other freewheels. That's a fact. " I think you just changed the subject entirely. Thought we were talking about the myth that there is some advantage in using the rear brake to instigate "weight transfer" to the front. Okay with me. You may present a "simple fact" in your view, but it pertains to a not so simple scenario. Until the rear wheel loses meaningful contact with the pavement, which is what happens at/near the limit of braking deceleration, the rear brake may be effective, but in that case, you sure aren't using the full stopping power available. At or near the point of maximum braking performance for a sport bike, the rear wheel is no longer supporting any meaningful load. If you are using the rear brake at that point, then the rear wheel will be locking up, which is absolutely not a desirable scenario as it can lead to loss of control and a high-side crash. "The difference between not using the rear brake and using the rear brake COULD be the inches you need to avoid hitting the object you're trying to avoid in the first place." In my view, and speaking from first hand experience wrt dry pavement only, more likely it will mean the difference between maintaining control versus momentarily locking up the rear wheel and risking a highside. The best advice I've heard on the issue of emergency braking is to head to a parking lot every now and then to practice emergency braking to get/maintain the feel for how aggressively one may brake before the rear wheel loses touch with the pavement. | ||
| Reepicheep |
I was doing little 2" stoppies on my XB9SX like clockwork on every "panic stop" excercise during the MSF advanced course. I was expecting to get "the talk", but instead got a thumbs up. Riding a 9sx on the MSF advanced course is like shooting fish in a barrel... | ||
| Court |
Good news . . . of the 1747 things you can do on a motorcycle . . . 1742 of them transfer weight forward. Need better news . . . forward weight benefits handling and stopping. It's a very happy world. | ||
| Fresnobuell |
What's wrong with 10% front brake application to get the weight to the front and then as much as you can handle after that....pretty easy if you ask me! Rear brake doesn't even have to be touched. **edit** (Message edited by fresnobuell on October 02, 2009) | ||
| Iamarchangel |
Read Court's statement again. The transfer happens anyway, rear braking is just one way of doing it. Don't get hung up on it. Don't learn steps, there will be no time for steps, learn to do it all at once. Okay, Bruce Lee school: when I first learned to fight, I thought a kick was just a kick, and a punch was just a punch. As I studied I learned that a kick was more than a kick and a punch was more than a punch. When I became a master, I knew that a kick was just a kick and a punch was just a punch, It's like that. | ||
| Jaimec |
Fresno: EXACTLY! | ||
| Blake |
"What's wrong with 10% brake application to get the weight to the front and then as much as you can handle after that....pretty easy if you ask me!" Nothing wrong with it. It's just a myth that it's somehow superior to judicious application of the front brake, the one with virtually all the stopping power. I am however wondering what you mean exactly by "get the weight to the front". Please explain. | ||
| Blake |
The way I look at it is from a perspective of minimizing my workload during an emergency stop. If I work just one brake instead of having to orchestrate the relative modulation of two brakes during an emergency stop, I think I'm better off, especially when one has the ability to instigate a rear wheel lock-up, loss of control and a high-side crash. | ||
| Fast1075 |
It's more like Zen and the use of the rear brake. I seldom use the rear brake except for that last bit before coming to a stop. I have dropped bikes at near zero speed from the front washing out due to oil or other debris. Other than that, on occasion if I am too hot into a corner (read that as misjudging a braking point) a little rear brake can settle the bike in without making it want to stand up. I have seen plenty of crashes where the rear brake skidmark led straight to the point of impact...way too many people have no idea how to use the brakes...back in the day, it was common to see bikes that had no front brake at all...deathtrap. Maximum braking is always going to be when the tire is rotating just barely slower than the road speed....maximum power application is similar...the tire is turning just barely faster than road speed. If the rear tire gets up a bit in braking...that is about as hard as you are going to stop...and if the front tire is just barely on the road accellerating or just a bit in the air, that is maximum accelleration...both are cases of maximum weight transfer...if the tire/road interface has grip, you are good to go. If you have the skill set to control the yaw and roll with a wheel in the air...even better...maximum effort is always going to be razor edge from loss of control...getting it right means getting stopped short of the Q-tip in the Caddy...wrong means you get wish-boned...dang I hate highsides...they HURT. | ||
| Court |
>>>It's more like Zen and the use of the rear brake. There is no "Zen" nor opinion to it . . . . it's simple physics. One of the reasons I maintain my "don't engage Blake in an argument on this stuff" doctrine . . . he does it everyday for a living and is good at it. But . . . I think I could whip him in a street fight.    | ||
| Fast1075 |
My point was that conditions constantly vary from second to second...and you must be aware, observant, and have the skill set to interpret the feedback and respond to the minute changes using awareness and muscle memory gained from experience and practice. I am but a simple mechanic with little in the way of formal education. But I have a desire to share what little insight I do have into the things that I have some small level of experience with...and I constantly seek it glean what nuggets of knowledge I can from my interactions with others. As a great thinker of our time would put it..a failed conclusion is simply the elimination of yet another of many possible scenarios. |
