| Author | Message | ||
     Midknyte |
Erik and his associates don't get near enough credit or recognition for their achievement with the ZTL brake and other innovations. The XB's, once you actually understand them, are an honest to goodness marvel. The way that so many parts do more than just their one assigned traditional job, resulting in fewer pieces and reduced weight. The sheer number of trick pieces on the bike. It's not just a bike that has been incrementally improved, with one new thing thrown every few years. They're a from the ground up purposeful, machine, filled with un-conventional solutions - any one of which someone "out there" will tell you should not work - yet there it sits, in harmony. The one really argueable point left being the Sportster derived mill - but that again is another part that Buell managed to make work. These things are purchaseable, made-it-out-the-door, rolling concepts that you'd otherwise only be ogle at in a tradeshow of one page spot of bragging in a magazine. Yeah, I love my Firebolt. | ||
| Jb2 |
I have a friend who has a nice collection of antique motorcycles. One of them is a late 10's Pierce with fuel and oil in the frame and an underslung exhaust. Pierce was touted as being way ahead of their time but their innovations never made it past the Great Depression. My 1909 Thor had an underslung exhaust with a manually operated valve that allowed it to bypass the muffler when a rider was "on the pipe". Perimeter brakes have been around for nearly a century as have overhead cams, 4 valve cylinders and superchargers. I will say that it took Erik and his Elves to turns basic ideas in to ZTL and Mass Centralization platforms that not only look good but function good as well. There had to have been an unmeasurable amount of hours invested into these ideas after their inception until they started rolling of an assembly line in East Troy. After Ford starting selling a V8 engine most other companies followed suit. After Buick developed and produced an overhead valve motor every car company then followed suit. Chevy built the Camaro because Ford built the Mustang. Think of how many motorcycle companies produced an inline four but it wasn't until Honda's acclaimed 750/Four that the design had matured enough and really caught on. Even BMW now makes one. This all seems like a natural progression of the market place. | ||
| Rocketman |
I don't believe I criticised the Buell system, nor claimed the Brakko one was better, but as a non mechanical / structural person I'm not thick enough to believe a brake placed at one side of a wheel rim will transfer braking load from contact patch to steering device the same as a braking load applied dead central to the wheel. The difference may well be marginal but I'd wager that centrally mounted brake will offer advantage over a side mounted single disc when braking in a corner. I'd further wager a more rewarding advantage will be seen if in an ABS system (they're coming to sportsbikes near you soon). That's an amazing design, and to dismiss it simply because Buell has a rather unique system too is just bloody stupid. Grow up. Rocket | ||
| Rocketman |
Ascot Pullin 1925 - British Fuel in frame. So what?  Rocket | ||
| Sifo |
Before the advent of the Buell ZTL, if you had asked the world's top sport bike engineers if they could trim 6 LBs from their production cast aluminum front wheel and brake assemblies while retaining excellent performance on road and track, they have laughed you out of their office. They struggle to trim mere ounces from the unsprung mass of the front end of their repli-racers. I never knew the claimed weight reduction was 6 pounds. That's a lot! Anyone know how much of that is unsprung weight? The wire spoke wheel has straight spokes. Spokes need to be set at an angle for strength. The torsional strength of the wheel is not as critical when the rotor is not mounted to the hub. This is why the "spokes" on the Buell front wheel are see through, but the back has a rib tying it all together. The radial lacing of the wheel allows for shorter spokes which will save a few ounces of unsprung weight. Good engineering for the system they produced. There are other things in their system that seem complicated. I'd like to see and exploded view diagram. | ||
| Froggy |
All of it.  | ||
| Sifo |
Boy Froggy, thinking about it you're right. That does make the ZTL system VERY impressive. | ||
| Ferris_von_bueller |
there is nothing new under the sun. | ||
| Aesquire |
Rocket, I could be wrong on the patent aspects. looked very like the ZTL as far as mounting goes. But I see a comment that it is structural to the rim. Hmm. Don't want to argue about offset load paths in the rim itself, as influenced by the lateral position of the rotor. I think I half agree with you there. On older bikes with less strong & stiff forks, one side brakes cause steering input. Hmm. Looks are in the eye of the beholder, and that one could look real good, or silly, depending. I am concerned about the load path from the caliper through the hub, and through the end cap of the fork. You want to pass brake fluid through a non rotating collar around the axle? That collar caries the whole braking load? Hmm.  | ||
| Gregtonn |
"I've done my homework and am uniquely qualified to judge technical innovation in the mechanical/structural arena." unique –adjective 1. existing as the only one or as the sole example; single; solitary in type or characteristics 2. having no like or equal; unparalleled; incomparable. Blake, I hope you will forgive me if I... Oh never mind. G | ||
| Rick_a |
Sure it's been done before, but the Buell rim mounted disc is obviously the most successful and arguably the best. Buell does not get enough credit. The tube frame bikes were an enduring design and much like mass produced customs, and the XB and 1125 series rolling concept bikes. I respect that. | ||
| Gregtonn |
"Buell does not get enough credit." I whole-heartedly agree. G | ||
| Swordsman |
Rocket, that is one weird ride you posted up there. Looks like a retro Chinese toy version of a motorcycle... like the stamped tin windup robots. ~SM | ||
| Rick_a |
...and the 'so what' is that it's the only one in a MODERN APPLICATION. plenty of oil in frames, though | ||
| Johnnylunchbox |
A friend of mine who is a brilliant engineer, and now works for NASA, but was previously a powersports (brand name withheld)engineer. He lauded the Buell chassis (the bike as a whole really) as one of the best he's ever ridden. I think he gave the Buell line credit. F the haters. You can hate the bike, or the man, but you can't say it's not a well-engineered bike. | ||
| Xb9er |
That wheel looks like what is on the "barracuda", what could have been bike. | ||
| Rick_a |
Not really. The "Barracuda" is an evolution of the ZTL2 wheel/brake with hollowed out "spokes" and petal type rotor. I've seen pics of a new monoblock caliper design as well.  (Message edited by Rick_A on December 03, 2009) | ||
| Blake |
Sean (Rocket), "as a non mechanical / structural person I'm not thick enough to believe a brake placed at one side of a wheel rim will transfer braking load from contact patch to steering device the same as a braking load applied dead central to the wheel. The difference may well be marginal but I'd wager that centrally mounted brake will offer advantage over a side mounted single disc when braking in a corner." Sorry Sean, your thickness is greater than you imagine. But it is VERY understandable. That is a very common perception by people. It can be a real mind bender for sure. The truth is that if all is properly configured/designed there is no discernible effect. The forks are just too stiff to notice. Gregg, You left one out... unique: 3. Characteristic of a particular category I only meant unique among the various other professions and resumés represented here. (Message edited by blake on December 02, 2009) | ||
| Gregtonn |
BBlake, "I only meant unique among the various other professions and resumés represented here." So as a mechanical engineer I would not be "...qualified to judge technical innovation in the mechanical/structural arena"? Golly, I'm sure glad the aerospace industry didn't think I was unable judge/create mechanical and structural innovations on the Space Station. Greg | ||
| Blake |
Apparently you'd be unique as well being that you too are in the particular (unique) category. Let's just keep this to ourselves though. The others may become envious. | ||
| Phillyblast |
Geez Blake, don't "brake" your arm patting yourself on the back. I mean, this isn't Rocket Scie^&^ . . . Oh, never mind.  | ||
| Rocketman |
I can't grasp that Blake. If a braking load is applied to my S1W front wheel with braking device placed to the right side of the wheel, are you saying the steering device only sees the load at the steering stem thus it makes no difference if the brake be placed outside to one side, outside to both as in a twin disc set-up, or central like Brakko? I believe the Buell twin disc arrangement was made to overcome some steering issues in racing environments when using a single disc of such large diameter. Whatever is the case the Buell ZTL and any similar system I'm sure perform great. In Buells case it looks fantastic and I would not say no to a Buell ZTL on my S1W. Just to remind all how good a ZTL type brake looks, here's one of the best S1W's ever seen.  Does anyone have a pic of an S1W with a XB front end? They look good too. Rocket (Message edited by rocketman on December 03, 2009) | ||
| Swordsman |
All I know is my bike doesn't pull to the right when I hit the brakes. That's what a degree in fine art gets ya.  ~SM | ||
| Rick_a |
That was to deal with the heat of slowing down 135hp Pro Thunder bikes. | ||
| Blake |
"are you saying the steering device only sees the load at the steering stem thus it makes no difference if the brake be placed outside to one side, outside to both as in a twin disc set-up, or central like Brakko?" That is an excellent way to state the situation, yes. The balanced force vector diagram (free body diagram) for the front end including tire, wheel, brake system and forks has the full braking load acting at the center of the contact patch. At the steering head axis it has an opposing force (m*a) and a couple (torque or moment represented by two equal and opposing forces) acting at the upper and lower steering head bearing centroids. However, if the forks were very flimsy, the one having to support the brake caliper could deform differently enough compared to the other to the point of being noticeable, requiring corrective steering input. If Greg really is as unique as I, then surely he'll find some time to throw together a nice free body diagram to illustrate the whole situation. (Message edited by blake on December 03, 2009) | ||
| Rocketman |
I can see how that would work in theory, but the mental block to me, the non structural engineer, wants to tell me it isn't so. Not that I'm up for the argument, nor do I disagree with your explanation, and just so's I can get my head around it I've a question. If we take a single disc equipped Tuber, XB or whatever, and the same again but twin disc, and fire it down the road in a straight line to say 100mph then as hard as possible pull the front brake on as sharp and hard as (not wanting to add other issues like amazing stoppies, lol), will both bikes brake in a similar fashion (excepting one may slow / stop sooner)? My brain wants to tell me they will, but there's a mischief perched on my shoulder who's encouraging me to believe the single disc will want to act on the steering head so much so it will turn the steering. If no steering deviation exist under such loads, then the Brakko system seems more aesthetic than anything else. Rocket | ||
| Rocketman |
That was to deal with the heat of slowing down 135hp Pro Thunder bikes. I didn't know that, or had forgotten it. When I spoke with Warrs about their Tuber twin disc set-up years ago, I do remember them saying they gained a handling advantage over single disc at some tracks. I seem also to remember a debate or three on BadWeB years ago about some torque steering issues with the single disc. Maybe that's to do with the brakes weight to one side, I don't honestly recall. Thanks anyway Rick. I can see how heat would be an issue on a 135 hp tuber. It was an issue for mine at 100! Rocket | ||
| Blake |
Sean, If in your 100mph emergency stop scenario the bike is being ridden by a human, then I;d say that there is no way that you'd detect or feel any difference between how the single or dual disk configurations behaved wrt tracking/handling. If you could put a robot on the bike and were somehow able to keep it perfectly upright and balanced and then locked the robot's arms so that there would be zero steering input, you might, just maybe be able to discern the slightest of difference in how the single disk bike tracks as it comes to a stop. It would likely be a LOT less discernible compared to the effect of a single sided swingarm. No one seems bothered by that highly eccentrically loaded bit of structure on some of the top sporting bikes. The rear wheel of a SSSArm chassis certainly moves offline just a slight amount under acceleration and/or braking, and/or with suspension action. | ||
| Midknyte |
Would not the tendency of our short rakes to make the bikes stand up, also counteract any miniscule effects of a single side brake? | ||
| Rick_a |
I have a dual factory disc set-up on my bike, and the main advantage is that I can run a stock set of pads and discs on the track without them overheating or fading. On the street the pads and rotors last about four times longer. If anything it's a hindrance to handling, as at high speeds it takes considerably more steering effort to initiate a turn. There's a few more pounds of unsprung weight, but I can't tell the difference as I revalved and resprung the forks at the same time. The extra weight also hurts acceleration to some degree...so there's a lot left to be desired. I'd use a ZTL and XB wheels, but I like keeping it old-school. |
