| Author | Message | |||||||||||||||||
     Djkaplan |
"Besides offering more braking power, there is another advantage to the dual disk configuration that no one has mentioned. I'm not sure how significant it is, but it would seem to tend to be an advantage." You hooked me on this one. Hmmm, is it the lower volume/surface area ratio of the smaller discs? Is it the greater heat dissapation from more pads and the larger volume of hydraulic fluid used? Come on, tell us! | |||||||||||||||||
| Imonabuss |
I just checked the contingency money payouts at FUSA and WSMC, and doggone, there's nothing in there relating Buell contingency money to what kind of brake you run. Don't think this is a question of balls, more a question of brains. | |||||||||||||||||
| Eeeeek |
Imonabuss, You are correct on that point. You could run a JAWA front end on a Buell and still be elligible for contengency money from Buell. Vik | |||||||||||||||||
| Davegess |
WOW, this topic is almost as bad as the synthetic oil topic  First did Buell "invent" the perimeter brake? NO, that is pretty obvious. What they did is develop (and I think patent) a wheel and brake "system" that uses the perimeter brake as a key part. The reason they did this is because it offers a significant savings in both unsprung and rotational weight. The primary benefit from this is better suspension response. This of course make the bike easier to ride fast on bumpy roads and will make for better braking on the same roads. I don't see anywhere that Buell claims this to be a better brake for racing than any other braking setup BUT it could be. The argument that no one but Buell uses it on race bikes so it must not be good is so illogical that it would have made the Jesuit who taught my logic erupt into laughter. There are many other factors effecting why they might not use it BUT the simple fact that it is patented by a competitor would pretty much make it impossible for a Honda or Yamaha team to use it. Plus most race team managers are very conservative. Small changes to a winning package and meticulous setup are the keys to winning. Small setps assure that you don't fall down or go backwards. Arguing that the bike you rode with it did not brake as well as the one that had a conventional brake is not much of an argument either. One would need to ride the same bike with and without the ZTL SYSTEM. Just using the perimeter brake would not cut it. Actually you might need to run a single and double disc ZTL and run it a variety of race tracks to really evaluate it. The question to be answered would not be, which feels better, or even which provides better barking, but which setup not only provides the right feel for the rider to be comfortable but also lets them go as fast as they are capable. And sometimes that means using a setup that does not feel right at first. Ultimately, if the lighter system provides faster lap times than it works even if it is an inferior brake. Sometime you sacrifice performance in one area to gain it elsewhere. Witness all the various ways that ultimate top end HP was reduced in 500 GP bikes. The winning bikes were tuned for less than ultimate HP to make them more ridable and to give the rider HP when they needed it. This reduced the top speed but made the bike faster. Now some have argued that it does not provide faster lap times because the Buells are not winning. I can hear that Jesuit laughing. Since the ZTL system is about 10% of the total FX racing package it could be the all time, trick, killer, never to be surpassed, wheel/brake system and the bikes would still not win races if the rest of the package wasn't up to snuff. Now the argument that I will give credence to is " for the way I ride I don't like 'em. They don't feel right to me, I don't like how they stop" That is a perfectly valid point. Doesn't make me or you right. I don't care if you like 'em or not I like 'em and think they are cool. | |||||||||||||||||
| Unibear12r |
A good point DJ I was only comparing single disk to single disk which is obvious. However, I got to get a look at a few dual disks this morning and their swept areas appears to be real close to the ZTL single by crude measurement. Also while the working part of a double disk that's just had a few stops was untouchable not so the carriers. Those floating supports that separate the carrier from the disk restricted heat flow a lot. Radiation would be a major way for heat to be shed from both types of disk. The calipers would stop or greatly reduce that in the area of the disk that it is at and look at how much more of the dual disk is covered by caliper. Gota be alot of other things that apply too. Not so obvious.  | |||||||||||||||||
| Unibear12r |
Good Job Dave. You just explained logical thought and testing in one post better than I've been able to in about twenty. Debate has never been one of my strong points. | |||||||||||||||||
| Anonymous |
Unibear, That was a thoughtful post two ago. Erik Buell has been working on cutting edge brake design since the late 1970s, and yes, did build and sell perimeter brakes long before Braking. His clad aluminum perimeter brakes were on Randy Mamola's prototype Suzuki RG500 test bikes in the early 1980s, as part of a project with Lockheed and Dymag. But, like many Buell ideas, they stay off the motorcycle product until they are much more refined. The fuel in frame patent goes back many years, for example, long before it came out on the XB. But to return to the topic, brakes are a much more complex system than most rudimentary calculations would have you believe. And Buell knows a lot about them. Suffice it to say that the thermal mass argument is absolutely antique in real brake design. Unibear, be proud that you figured out one of the many factors that make the ZTL work, and it didn't take you 20+ years!!!! I know I'm not supposed to post anonymously, but others have, Blake won't turn me in, and I can hope that the management at Buell doesn't figure out who I am! No more posts for a while. | |||||||||||||||||
| Bbstacker |
It seems to me that the brakes on a motorcycle (any motorcycle) work better when there is a rider on it. I think everybody needs to do themselves a favor and get on their bikes and check out the brakes...after you get a long way from point A and are still quite a few miles from point B. I think you will find your brakes work just fine.  | |||||||||||||||||
| Unibear12r |
Thank You Anon! Bb you are so right. (Message edited by unibear12r on October 22, 2005) | |||||||||||||||||
| Blake |
Chop, You're right, I misinterpreted your "who was first" post. However, you did get the comprehensive answer and then derided Imonabus for providing it. But I agree with your later assertion, that issue is neither here nor there. Imagine if Buell went to an even lighter forged wheel and slotted disk? In military aircraft construction they have this really neat process of superplastic forming a contiguous titanium honeycomb type sandwich panel. They take two sheets of Ti 6AL4V and spot weld them together in some optimum open cell (no areas enclosed totally by weld) pattern. Then they weld all around the perimeter of the sheets, sealing their interior to be comletely air-tight. They then place the conjoined sheets in an oven/furnace between two pefectly flat very rigid well-supported tooling plates that are spaced about a quarter inch or more apart than the conjoined sheets total in thickness. They hook up a high pressure nitrogen source, heat the conjoined sheets to superplastic (yellow hot) temperature, then blast the high pressure gas in between the sheets. The sheets are forced apart as you would expect with all the spot welds ending up as tiny webs and columns connecting the two facesheets. Just like a honeycomb sandwich panel, but all contiguous metal. Reall really cool process. What you end up with is a very strong, very lightweight sandwich panel. I wonder... could the same technique be applied to stainless steel towards a superlight well ventilated brake disk?  If only I were a billionaire. I'd be doing stuff like that in my back yard shop. | |||||||||||||||||
| Blake |
Jim, You are right. I was thinking Laguna Seca but the race was actually at VIR. Fourth place is a great finish. Fifth place is a great finish. You won't finish so well in an AMA Professional road racing national series if the brakes on your race bike don't work well. It is a very simple and irrefutable concept. Yes, the sketch is not to scale. It is however illustrative of the point the man was trying to make. That a larger disk increases braking power. Quite a few Japan Inc repliracers come equiped with 310mm disks. You know why Japan Inc switched to smaller diameter disks? They were desperate to save a few ounces of unsprung weight. Buell found a way to save pounds. Advantage - Buell. | |||||||||||||||||
| Blake |
Also indicative of the caliber of the Buell ZTL brake/wheel was when Mike Cicotto just four seconds back of Vincent Haskovec beat the likes of Larry Peagram, Pascal Picotte, Danny Eslick Mark Junge and Heath Small at Road America. You don't beat racers like that if your brakes aren't working well. | |||||||||||||||||
| Blake |
Do you think that maybe the Buell ZTL brake might be improved and developed further for racing? No? Just give up and call 1-800-Brembo? Not sure folks who subscribe to that kind of thinking ever innovate anything. Pretty sure they don't in fact. | |||||||||||||||||
| Court |
>>>a little company called Pittsburgh Performance Products made some stainless clad qaluminum brake rotors Hey . . . I know that company. Kid working his ••• off to get through college, wasn't it? | |||||||||||||||||
| Henrik |
I thought I remembered Pittsburg Performance Products was Erik Buell's company. All in all a great discussion - no need to get upset. Especially not about disagreeing. Agreeing that it's OK to disagree is always a good basis for a discussion. Besides, it's a good day when I have a chance to learn something new. Bb;  Henrik | |||||||||||||||||
| Benm2 |
Imagine if they went to TWO slotted disks with FOUR piston calipers? The WHEEL would still be lighter... | |||||||||||||||||
| 650 |
I'd like to have a front end and wheel designed around a CMC ZTL brake system. While it would cost a fortune probably I think it would be pretty sick. | |||||||||||||||||
| Blake |
DJ, I was thinking about how a single disk front brake imparts a bending load into the one fork leg that supports its caliper. So if the fork, axle and axle to fork connection are insuficiently rigid, the brake-side fork could deflect more than the non-brake-side fork and influence handling. However, take note of the positioning of the brake caliper. Note that it is located so that loking at loading in the forks tube, as you travel from the bottom of the inner fork tube up towards the intersection of inner and outer fork tubes, the moment due to brake caliper loading drops to zero. The line of action (dotted line in diagram below) of the brake caliper/pads acting upon the fork aims straight towards the uppermost portion of the exposed inner fork tube, thus optimally reducing the flexural effects of that load, the single largest load acting on the forks. This leads to the suggestion that Bill (Reepicheep) made earlier about adding a 2nd caliper 180 degs opposite the existing one. That would liekly have a detrimental effect on the fork flexure as it would impart a significantly larger bending moment upon the inner fork tube near its uppermost exposed length. Some pictures (free body diagrams) are worth a thousand words... See if they make any sense without annotation. Arrows indicate loading of fork/brake caliper assembly under 1g stopping force. Size of arrows reflect magnitude of load. Red are applied loads (weight and inertia of bike/rider acting upon front forks); blue are reaction loads (those loads supporting/counteracting the applied loads). All horizontal load components must sum to zero. All vertical load components must sum to zero. All bending moments must sum to zero about any point. This is a refresher statics course for Bomber. Hope he's paying attention. ![: ]](http://www.badweatherbikers.com/buell/clipart/proud.gif)  Fork With Caliper  Fork Without Caliper  Fork With Two Opposing Calipers, aka the "Billbrake"  Note how in the first FBD of "Fork With Caliper", the axle is actually being pulled upwards by the lower fork tube. I had to look twice at that to be sure it made sense. What do you note about the dual caliper configuration? The effects of bending are at play in significant measure in the fork and brake relationship. fun stuff. Doesn't look to me like a well layed out single-sided brake system would cause asymetrical deflections of any consequence. So... never mind.  (Message edited by Blake on October 22, 2005) | |||||||||||||||||
| Blake |
Ben be brainstorming. I like that.  It's the most fun an engineering weenie can have. Well aside from getting to track test the prototypes. (Message edited by Blake on October 22, 2005) | |||||||||||||||||
| Blake |
Interesting to note that Kawasaki is using 300mm rotors on their repliracers, even the ZX-10R. Honda runs 296mm rotors on their CBR600F4i. I wonder why they downsized. Pretty sure it wasn't too long ago they were using 320mmm or even 330mm disks. Why would they sacrifice braking power for less mass and unsprung mass at that? Silly engineers. How could they possibly make improvements to an existing proven system?  Of course those are not the brakes that Honda racers use on the track are they? Less unsprung mass is what the ZTL is all about. But while the Japan Inc engineers were busy working diligently to improve the performance of their front wheel/brake/suspension systems, Mr. Buell picked his head up out of that darned box and saw a different approach that would carve not just a few ounces, but multiple POUNDS from the front wheel/brake assy thus vastly improving suspension performance. | |||||||||||||||||
| Eeeeek |
I think the idea of ZTL is solid and that it has not yet reached its full maturity. In it's current incarnation, the XB braking system is not better than what we're seeing in the racing circuits. It has potential to be better and in ten years may very well be the norm. This discussion is about the hear and now, though, and the tradtional systems are providing better results. Vik | |||||||||||||||||
| Blake |
WTF? How can you delude yourself into such brainwashed thinking? I mean THAT is COMPLETElY rational and well said. | |||||||||||||||||
| Jima4media |
Blake, I will give you that a couple of Japanese manufacturers have switched from 320 to 310mm rotors on their street bikes. Others like Honda, have gone from 320-330mm to 310mm and for 2006 they are back to 320mm again. Most factory manufacturers and privateers racing setups are usually 320mm rotors and radial Brembo calipers. Aprilia, Yamaha, Ducati, KTM, and others have 320mm on both street and racing setups. MotoGP racing is all 320mm with carbon and composite ceramic rotors. Yamaha, Honda, Ducati, Kawasaki, Suzuki, and WCM. In the final analysis, it is not whether you have 296mm or 375mm rotors, it is how well the brakes work as a whole. It is not only bikes that used Brembo. How about Ferrari street cars, and Formula 1? Mc Laren, Renault, and Toyota? How about Champ Cars, IRL, NASCAR, American LeMans, GT and Grand-Am cars? If you want to go racing, you choose Brembo. http://www.brembo.com Jim (Message edited by jima4media on October 23, 2005) | |||||||||||||||||
| Reepicheep |
Cool analysis Blake! Neat stuff, what you are describing makes perfect sense. I was actually thinking of something pointing as close to straight up as possible, but it still has the same issue. Gee, it's almost like the designers thought about where that thing is and where it should point Real genius is finding the one apparently simple solution in a sea of possible approaches. I love my Buell. Disciplined Genius at work. I can find discipline, and I can find genius, but when you get the two together, you have something very special. (Message edited by reepicheep on October 23, 2005) | |||||||||||||||||
| Al_lighton |
I've avoided posting to this discussion completely, biting my "tongue" on several occasions. But Jim just wrote: "In the final analysis, it is not whether you have 296mm or 375mm rotors, it is how well the brakes work as a whole." I think it was not quite worded properly, though was very close. It should have said: In the final analysis, it is not whether you have 296mm or 375mm rotors, it is how well the motorcycle system works as a whole for the intended application. And that's all I have to say on the subject, other than that I think ZTL works marvelously for the street application, the only one I have personal experience with. I'll go climb under my rock now (since Wilma is less than 12 hours from what appears to be a direct strike on my present location, so I hope it's a big enough rock). Al | |||||||||||||||||
| Blake |
I agree with you Al. I got some more for my good friend Jim though. ... "I will give you that a couple of Japanese manufacturers have switched from 320 to 310mm rotors on their street bikes. Others like Honda, have gone from 320-330mm to 310mm and for 2006 they are back to 320mm again. " That may be true for literbikes, but let's check on the accuracy of that statement wrt the Japan Inc repliracers against which the Buell Formula Xtreme bikes compete. Front Brake Disk Diameters
Sorry buddy, to say that "a couple of Japanese manufacturers have switched from 320 to 310mm rotors on their street bikes. Others like Honda, have gone from 320-330mm to 310mm and for 2006 they are back to 320mm again." is simply not true. But I do believe you that the AMA racers ando other high caliber racers the world over do indeed use dual 320mm disks on the track. So apparently the brakes that come fitted on all the Japan Inc. 600cc Supersport repliracers are inadequate for racing. Apparently the stock brakes including the calipers, heck the entire front brake system of the Japan Inc. 600cc Supersport racing machines needs to be replaced with a bigger, stronger, more expensive aftermarket brake system. So they call 1-800-Brembo. I agree, Brembo and provide top notch brake systems. No doubt. But considering all that, would you care to restate your point wrt to stock Buell ZTL brake system again? You know, the same exact brake system that the Formula Xtreme racers are using? yeah they are developing an 8-pot racing caliper, but the disk remains 375mm. More stock than the Japan Inc. racing systems no? Owned. (Message edited by Blake on October 23, 2005) | |||||||||||||||||
| Jon |
Hey Reep, I'm no genius, but I am working on discipline in my life. And I do love my Tuber Buell! For the record... I invented disk brakes, the sewing machine and honey basted ribs. Anybody got a problem with that? Seriously, I think this thread has been and is, just great. As a purely recreational rider and construction estimator (read, not a motorcycle tech) I am getting an education on the concepts and forces involved in braking (again!). And it's great to have Buell factory folk drop in and provide the facts for the edification of many. Right on Buell! Where else can you get this? | |||||||||||||||||
| Eeeeek |
Anony: You could have corrected me instead of just calling me an out and out lier. My statement about Buell having a financial hold of some of those teams to run ZTL is true. Is this statement correct: Buell does not give monetary support to teams that do not run the ZTL front end; therefor, if you want monetary support from Buell, you must run the ZTL front end. Vik | |||||||||||||||||
| Grndskpr |
I agree with you Al But considering all that, would you care to restate your point wrt to stock Buell ZTL brake system again? You know, the same exact brake system that the Formula Xtreme racers are using? We also tried a spacial 'factory' front disc that was 1mm thicker than stock, along with their pads. + Nissin factory only front rotor, thats 8 piston, is what i consider far from stock SOOoooo The reality of the matter is, if you double the factory HP of a formula extreme bike, niether brake system is up to the task on a race bike, so both need to change to a more race oriented braking system INline 4's try and stay close to original for that stock look( so they can sell there bike to the public), as does Buell(so they can sell there bike to the public), but in the end there both better than you average street bike, and as a rule almost unavaliable if you wanted to buy the same set up. And as it stands, Honda rules the roost in Formula extreme, that may change, but i think its going to take more than brakes R | |||||||||||||||||
| Djkaplan |
" I got to get a look at a few dual disks this morning and their swept areas appears to be real close to the ZTL single by crude measurement." [Please bear in mind I'm not arguing for or against the ZTL brake system, I'm just pointing out assumptions I think are incorrect] I can't see how this could be true after doing a few cursory calculations. The XB disc doesn't have the same swept brake area compared to 300mm discs with smaller pads. I had to make a few assumptions about pad size, but it seems that the dual disc may have more area covered by the pads, but it also has more area exposed. Radiative heat transfer is also a funtion of area - granted, in a dual disc you have two hot objects next to each other instead of one large one. |
