| Author | Message | ||
     Jgarner99 |
Wrong. | ||
| Blake |
DC is right. Mike, I understand inertia and that a hoop of same mass will have double that of a disk. I just don't see how you figure a wheel of any sort is a hoop. The rim and tire fit that analogy, but those remain for either case of spoke type (solid disk or spokes). Are you saying that the rim of a solid wheel would be less massive? I can't see it. Something was goofy with your bicycle wheel demo. Possibly due to a much less massive carbon disk versus a much more massive conventional wheel. Too many variables other than form of spoke to draw any conclusions. | ||
| Jgarner99 |
Rats. I hate it when I do that. I read "hoop" and "solid" too many times and got them conflubbered. Sorry, DC, didn't mean to snub you. Thanks, Blake. My goof. | ||
| Jgarner99 |
I've really got to start doing what my boss says, and keeping my mouth shut. | ||
| Elvis |
The basic pysics and moment of inertia discussions are accurate, but, as Blake points out, the flaw is that we aren't talking about a system with a fixed amount of mass in which we can put the mass anywhere we want. We actually have to connect a hub to a rim and take into account MANY more variables than mass. If we could put the mass anywhere we wanted, we'd put it at the center . . . building a magnesium disk around the hub would have the lowest theoretical moment of inertia . . . but it wouldn't do what a wheel needs to do. Now, with this discussion in mind, take a look at some of the close-ups of the 1190RS wheel and you'll see some of the things that struck me when I first saw it. Notice how the members are broader toward the hub than the rim? That directly addresses this moment of inertia discussion. It would seem common sense (after we see it) to use such a design, but look at other wheels (including previous Buell wheels) and you'll see that they generally aren't much thinner at the rim than hub. In addition to that, look at the actual shape and arrangement of the spokes. You can see that the design will provide a lot of strength from side to side. So when the bike is leaned over and going over bumps, there is a lot of structure that will prevent the rim from going out of true with the hub. The sacrifice of that arrangement is there is not as much structure to resist the forces that will be present when the brakes are applied. Typically, those braking forces applied to the hub will distort the wheel as, for a brief moment, the hub is going slower than the rim. . . . but the rim-mounted brake allows a design that wouldn't be possible with more traditional brakes. That's what I noticed when I first looked at the 1190RS front wheel. It is a very specific design that takes advantage of the unique characteristics of the rim-mounted brake. It appears to have great side-side-strength but poorer twisting strength (in terms of the forces that result from hub-braking) - exactly as it should. And yes, with the simple idea of moment-of-inertia in mind, it concentrates more mass toward the center. So this design is clearly preferrable to a solid disk . . . but there's much more to it than that. You could probably spend a week in an engineering class doing nothing but studying the design of that wheel and comparing and contrasting it to other designs. (Message edited by elvis on February 27, 2011) | ||
| Blake |
I'd really enjoy having the chance to structurally optimize a ZTL type front wheel & brake system, aircraft style. Looking at the front wheel on my Uly, it looks like there is potential for significant mass reduction at the rotor carrier mounts. The constraint of designing for a casting is probably preventing some additional weight reduction. If only money were no object. ![: ]](http://www.badweatherbikers.com/buell/clipart/proud.gif) | ||
| Lemonchili_x1 |
When I was a lad (man, I'm getting old, hehehe) I used to work as a lab tech in an electronics lab in the Mechanical Engineering Dept of a university. My boss was an ex-Navy electronics engineer who was a very "real world" engineer. One of his favourite past times was stirring up the academics. One day he independently went to three of the professors and asked if they would calculate how big the diagonal cross brace should be for his side gate, wondering how different their solutions would be. He was right, they all calculated by different methods to come up with braces varying in size from a cane whip to a fence post  My point? Not any really except that sometimes, despite all the analysis in the world, you have to start somewhere logical and practical, say a 2x4, and then test it in the real world (or the race track) and refine it into something that works (and wins). Overall I think Jens equation is the most accurate: You win = you right (-:  I will throw a couple of factors into the argument just for fun... 1. Does the ZTL system still hold as big an unsprung mass advantage as it used to? A 2008 CBR1000RR front wheel (OEM street wheel with bearings, no discs or tire) weighs 8.2 lbs (source: Padgetts Honda) which is really impressive. The original (OEM street) ZTL1 wheel weighs 8.8 lbs (Source: Fuell article Jan/Feb 2003), the ZTL3 wheel would be lighter but how much? 2. Conventional twin disc systems are not immune to fade either. (This is pretty much conjecture on my part from different bits and pieces I've read on the internet, so it must be true ) | ||
| Jdugger |
> 1. Does the ZTL system still hold as big an unsprung mass advantage as it used to? No. Because we are comparing a circa 2002 technology wheel (the Buell wheel) to a 2008 technology wheel. As I pointed out in one of my posts, the Japanese makes have come a long way with wheel weights in that time, and their wheels today are significantly lighter than when the 6-lb figure was quoted. The OEM Buell wheels are not a premium wheel. They are a low-cost, cast product that's not particularly light for it's strength. As delivered in 2002, the Buell ZTL was as much a way to deliver a far less expensive product with the same performance as a more expensive wheel as it was anything else. If one were willing to spend a little money, one could easily have a dual-disc setup using something like forged Mg wheels at weights lighter than the OEM ZTL setup. Also worth considering is the ZTL2 caliper is a heavy, heavy block of metal. It doesn't have the weight advantage over the twin caliper set-ups the original ZTL did. I think it's fair to say a circa 2010 Buell wheel (like the new 1190 wheels) could regain an advantage, but the wheels we have on our bikes now don't have it. And the advantage to be had is getting smaller. I'd put my left nut on the 1190rs not having a 6-lb system advantage (wheel, rotors, calipers, fluid) over something like the CBR1000. If it does, that's *really* incredible. And, the Buell rear wheel system including rotor and pulley is probably the most heavy one out there of modern (say Model Year 2009+) competitive sportbikes. It's ridiculous how much more heavy it is than something like a ZX-6 wheel. Even my tire guy at the races comments about it. The 1190rs will probably fix a lot of that, too, but I kinda giggle when I hear about "unsprung weight" regarding that rear wheel. That thing is ridiculously heavy. > 2. Conventional twin disc systems are not immune to fade either. Absolutely they do. That's never been debated. The debate was more along the lines of which system would fade sooner, all things being equal. | ||
| Zac4mac |
The braking forces are never felt by the spokes or hub of the ZTL. Seems those parts should be lighter than "conventional" wheels. (Message edited by zac4mac on February 27, 2011) | ||
| Blake |
JD, >>> I'd put my left nut on the 1190rs not having a 6-lb system advantage (wheel, rotors, calipers, fluid) over something like the CBR1000. Sounds like we have a serious challenge. Of course the rotor carriers, axle, assoc. hdwr. and spacers need to be included too. Thing is, even if the advantage is just a few pounds, that is HUGE. Just ask the Japanese engineers who spend all year trying to shave mere ounces from the unsprung mass. | ||
| Jdugger |
I agree 100% Blake... but it will take a fisherman's scale and an 1190rs to find out. I don't even think it's more than 3lbs now, but the safe bet was "it's less than 6". I have no data other than lifting fellow racer's wheels. Circa 2002 when all those statements were first made it was very much true, but times have changed... Weigh: Buell 1190rs fork set vs. Ohlins R&T raidal caliper fork set Buell ZTL2 (or 2.5, since it's prob lighter) vs. two brembo monoblock calipers Wheel vs. wheel, with rotors mounted SS lines, full of fluid / 2 I suspect axles, spacers and etc to be about the same since they are required on both bikes, but I'm happy to throw them in. On a 2009 vs. 2009 production bike, I know you are in for a big surprise. It's no where near a 6lb delta, and I actually suspect the ZTL2 to be at a disadvantage. On an 1190 vs. 2010 Honda/Kawi/Yammi, I suspect the 1190 to have a modest advantage of less than 6lb, but don't know for sure. | ||
| Xoptimizedrsx |
so do we use air or nitrogen then? figured I would add that to the pot... Nice points Elvis. I knew I was not completely crazy. Now for a company to figure out how to put the tire/s on a diet... lol The rim/s alone is one thing but with tire mounted, well you got to start all over. The further inward(closer to Axel) the mass the better on complete mass. I agree with Jens as well you win, you are right. Go Erik Buell Racingracing... | ||
| Lemonchili_x1 |
I did some digging about 18 months ago when I thought about upgrading the brakes on my X1, so for the street bike comparison... 2008/2009 Honda CBR1000RR (non-ABS) Front wheel (with bearings and bearing spacer) 3.7kg (8.2 lbs) Front Rotors (Inner and outer, no bolts) 1.218kg(2.69 lbs) each (or 5.38 lbs for two) Front calipers (without pads, bolts, banjo fittings) 0.709kg(1.56 lbs) each (or 3.12 lbs for two, without pads) Wheel+rotors+calipers = 16.7 lbs (no pads, no bolts, no tire) Buell ZTL/ZTL2 ZTL Wheel (from Fuell article, Jan/Feb 2003) 8.844 lbs ZTL Rotor (from Fuell article, Jan/Feb 2003) (Is the 1190RS rotor lighter or heavier?) 3.563 lbs ZTL2 Caliper (with OEM pads) 4.25 lbs Wheel+rotor+caliper+pads = 16.7 lbs (no tire, no bolts) Someone please check I've added that up correctly  (Note that the CBR1000RR calipers are quite small so I suspect the pads wouldn't weigh a lot, 2 maybe 3 lbs for both sets but I'm really guessing) I remember digging around for info and did find some weights for race wheels (6 lbs rings a bell) and Brembo race calipers but I don't know where I've put it. Remember there is a magnesium race version of the ZTL wheel which is used on the Erik Buell Racing 1125RR and the pegasusraceteam 1190RR. I read the weight reduction somewhere but can't remember what it was. | ||
| Blake |
JD, Let me understand you clearly; you are characterizing a multiple LB advantage in unsprung mass versus the next lightest contender as "a modest advantage"? Really?  With respect to weight, one may just as well say that a CBR1000RR has "a modest advantage" versus a V-Rod. Buell axle has no nut or outer spacers. There's also the extra brake line and fluid. Accounting for brake pads, Chili's numbers indicate that the old ZTL wheel + brake assembly still had a 2+ LB advantage. The 1190RS wheel is almost another 3 LBs lighter (6LBs vs. 8.84 LBs). So that seems to indicate at least a 5 LB advantage for the 1190RS. Is your left nut starting to ache yet? | ||
| Jdugger |
> Let me understand you clearly; you are characterizing a multiple LB advantage in > unsprung mass versus the next lightest contender as "a modest advantage"? Really? Really. First, I don't think that much advantage exists anymore, comparing 2009 vs. 2009 production models, for example, and second, no I don't think it's that big of a deal for the average track rider vs. better brakes. What you need to do is read up on some of the racer's comments of upgrading to forged Mg from OEM wheels on nearly any brand. The difference isn't night and day at all but the very highest levels of riders. AGAIN: Come to the track, learn how to ride *well*, then make your informed opinion. You have all of the engineering knowledge, drank plenty of kool-aid, but none of the practical experience or skill in the seat to draw from. In my garage at the track, I have OEM wheels, Buell race cast Mg wheels, March forged Mg 16.5 wheels -- we can try them all on your bike so you can tell me what differences you feel. > Is your left nut starting to ache yet? Scales and a bike, son; Scales and a bike. Brake pads don't weigh 2lbs, and neither does the difference between the Buell front axle (which is decently heavy in it's own right) and a comparable Honda one with the nut. Either way, you still aren't to 6lbs, which was the original wager. Remember, I *have* a 2003 CBR600RR and my buddy has an 08 CBR1000RR. Both are in my garage at the track, so we can pull parts and do some side-by-sides and get real data. I've changed plenty of tires on both and have a pretty good feel for it. I'm telling you the vast difference in weight ain't there. (Message edited by jdugger on February 28, 2011) | ||
| Drawkward |
Blake, PLEASE take JD up on his offer. JD, PLEASE invite me too if it ever happens! I'll make the trip up. | ||
| Blake |
JD, So now you are saying that a lighter front wheel doens't make much difference? Really? It seems that you're dodging the issue, backpedaling in a dead sprint, and creating an army of straw men to defend your retreat. Saving multiple pounds in unsprung mass is no big deal you say? Dude. The motorcycle wheel engineers in Japan just called; you've dishonored them, their work, their families, and their employers. This aint' gonna be pretty. Really. First, I don't think that much advantage exists anymore, comparing 2009 vs. 2009 production models, for example, and second, Lemonchili's numbers indicate about a 2 LB advantage for the Buell ZTL system versus 2009 Honda CBR1000RR, which is incredible given the six or seven years gap in development. But I thought we were talking about the weight advantage of the new 1190RS front wheel and brake assembly? Try to stay focused. no I don't think it's that big of a deal for the average track rider vs. better brakes. "For the average track rider? You've introduced a new parameter to the discussion and possibly an apparent straw man. "Versus better brakes? You've invented another straw man seeming to imply that the 1190RS brake is not up to its task. That would be false. The "better brake" is the one that allows a better lap time or better control on public roads, yes? Again--this is becoming tiresome--let's let history be our guide: In only its 2nd race outing of 2008 and piloted by rookie superbike racers, the 1125RR was seen battling Larry Pegram on his Ducati 1098R for 4th position. I guess the braking was holding them all back?  If keeping the rubber on the pavment is important, reduced unsprung mass is a major factor, at least for any surface that is not perfectly smooth. It's not kool aid. The laws of physics are real, no getting around them. The front wheel cannot rebound more quickly than its natural frequency ( Fn=SQRT[K/m] ) allows. The laws of physics dictate that the quickets possible rebound rate varies proportionally with the square root of the unsprung mass. This means that if the unsprung mass is reduced by 30%, the suspension will be able to react 14% more rapidly. Furthermore less unsprung mass then requires less damping which further enhances the capability of the suspension to help maintain traction. If the 1190RS front end unsprung mass is 6 LBs less than that of the CBR1000RR, that equates to around what, a 30% advantage? Seems significant to me. What you need to do is read up on some of the racer's comments of upgrading to forged Mg from OEM wheels on nearly any brand. Where? I found the following testamony concerning the effect of lighter weight wheels on lap times: Racers are reporting lap times of 2.5-3.0 seconds faster with Carbon wheels over the stock wheels and 1.5 seconds faster over magnesium wheels. From a review of the Ducati Desmosedici RR: Also for the first time ever, this Ducati production motorcycle features Marchesini forged and machined magnesium alloy wheels, with 7-spoke design as on the GP6. This enhances the handling and improves suspension response by reducing unsprung weight and inertia.Poo?  The difference isn't night and day at all but at the very highest levels of riders. "The difference isn't night and day"? That's another straw man requiring an extreme level of contrast in order to be judged positively. The appropriate measure is "significant", not "night and day". But then you do state that "the difference (is) night and day at the very highest levels of riders"? That would seem to suggest that less unsprung mass is a major factor then. I'm confused, which is it? AGAIN: Come to the track, learn how to ride *well*, then make your informed opinion. I'd like to think that I've already done that. You have all of the engineering knowledge, drank plenty of kool-aid, but none of the practical experience or skill in the seat to draw from. I've run 1:35 at OHR on my old '97 Buell Cyclone, at the time pretty slow, about 12 seconds off the outright motorcycle lap record at the time (2002). Does that qualify as "practical experience or skill in the seat?" I've also taken an XB12R around for a few laps. It felt significantly better planted over the rough stuff. In my garage at the track, I have OEM wheels, Buell race cast Mg wheels, March forged Mg 16.5 wheels -- we can try them all on your bike so you can tell me what differences you feel. The Uly is a less than optimum choice for a track bike, and I'd not want to push it to demonstrate the point. I just cannot get over the fact that you are here actually arguing that a reduction of multiple pounds in unsprung mass is insignificant. It really is quite bizarre. >Is your left nut starting to ache yet? Scales and a bike, son; Scales and a bike. Brake pads don't weigh 2lbs, and neither does the difference between the Buell front axle (which is decently heavy in it's own right) and a comparable Honda one with the nut. Either way, you still aren't to 6lbs, which was the original wager. I'll take that as a "yes", grandpa. Remember, I *have* a 2003 CBR600RR and my buddy has an 08 CBR1000RR. Both are in my garage at the track, so we can pull parts and do some side-by-sides and get real data. Seems like Graham (Lemonchili) has already done that for us, no? But hey, that's cool; go for it. I'll be interested in the results even though they won't speak directly to the 1190RS, the topic of this thread. I'm telling you the vast difference in weight ain't there. "Vast difference" versus the old version wheel? That's another straw man. I think the pertinent word is "significant", which to me would be anything better than a LB or two for the old version versus today's best in the repli-racer literbike class. It's pretty simple JD, when it comes to what is desirable and what works on a motorcycle, I believe Erik Buell and Steve Anderson. I believe the results of the Pegasus Race Ream last year. I believe the results of the RMR/Geico team in 2009. I accept the wisdom of the Pegasus Race Team's manager, Jens, who holds that "what wins, works." Did you catch that they won their championship walking away and even won an Open Superbike race, by a margin of 7.5 seconds? Those darn brakes. When you consider the advancement from ZTL-1 to the current 1190RS system, all in just three short years, imagine the next version, yet another LB or two lighter with even more enhanced heat dissipation, or the 2014 version with a forged magnesium wheel and a lighter ceramic rotor. The future of Erik's brake concept couldn't look much brighter. The engineering achievement is inspiring. That's not kool-aid; that's just simple observed truth. (Message edited by blake on February 28, 2011) | ||
| Xoptimizedrsx |
ahhh? "Ouch"!!!! All I know is I will watch in the International horseshoe Next week. A Buell or Two will Out break many a Import bikes. Just as they do every year...  | ||
| Jdugger |
Club Fanboi Unite! Lemon's numbers seem to imply the weights are pretty comparable. Where are you getting the two lbs from? The *shipping weight* on a set of pads is 1lb, so it's not that. What did I miss? My bud's CRB1000RR is in my garage at the track with the front wheel and forks off of it right now, so if my shoulder feels up to it this weekend (it should), I'll take my crashed race bike out there to work on it, and do some weights while I'm there. I can put the axles and so forth with both, and this will be loaded weights with hardware and tires, too. I'll find out. If you know the delta between the original xb wheel weight and the new 1190 wheel, we can then at least guess at the difference. I'm not trying to deflect or strawman you -- I'm trying to talk a little sense and reason into your belligerent fanboism that can't see any side other than the "buell must be better one." If anything, I'll drag up the old brake/heat thread and give the class a demonstration of how many times you spent trying to deflect the issue to the brake caliper mounting discussion and who can remember what else you tried to drag into that. It's not been 3 years since ZTL's introduction, it's been 8+. As for the track invite/bike issue, you can have my B bike for the day. It's an 09 1125r with the Erik Buell Racing race suspension kit installed and Pirelli Superbike slicks. It's very nice -- and actually my personal best at Motorsport Ranch Cresson was set on this bike. I'll ride my 550cc motard if my race bike isn't rolling by the time you come out -- it's pretty fun, too. Until then, let's get a scale. I've swapped too many tires on all these different bikes at this point, and I know there isn't much difference in them. Ironically for this discussion, the Buell rear wheel assembly is heavier than the Honda. I won't know exactly how much until I weight it, but I'm guessing 5 lbs or so. (seriously) It's pretty striking. You notice it the second you lift it onto the nomar. So engineer this: If unsprung weight is such a critical factor as you suggest, which is more important, front or rear? And, if they are not equal, what is the balance, as in so much of x is worth so much of y? Seems like to me rear wheel weight is at least reasonably critical, gyroscopic forces and all. Have we moved on from heat dissipation to wheel weights now, or should we do as you suggest and try and keep the focus? | ||
| Court |
Actually . . a couple years ago there was a story about how much Honda had spent to peel something like 2 pounds off their race wheels . . . it was in the 7 figures, the amount of R&D and it didn't bring them anywhere near the Buell weights. I'm sure the story got embellished but the facts remain that a little group of Elves from East Troy did what Honda couldn't. I think that advantages of the lower unsprung weight provide more benefit to me . . riding on bumpy public roads . . than to the "very highest levels of riders". Just seems intuitive. | ||
| Jdugger |
> Just seems intuitive. It's not though. I've set personal bests on the OEM wheels using shagged endurance slicks on my B bike that's fully 25lbs heavier than my race bike. I have Mg wheels that are 2lb lighter in the front and just more than 3 in the rear (I think) and to be honest I'm really not sure it makes much of a difference. I'm also very much an amateur rider, but there's just no way I have the consistency to be able to measure the 5lb drop in weight between my Buell race wheels and the OEMs in terms of laptimes. Again, I really encourage you to come out to the track. I've got the bikes, I've got the various sets of wheels, etc. You can try it for yourself in a consistent environment. Also, keep in mind that race tracks aren't smooth. At least the ones in Texas are incredibly bumpy, certainly as much or more so than country back roads would be. I think what Buell did with the ZTL was figure out a way to use a cheap cast wheel and have it deliver performance comparable to a much more expensive solution for the typical rider. The money saved could be used in other ways to better the bike. I'm not knocking that ingenious bit of engineering, but that doesn't make the system outright better. (Message edited by jdugger on February 28, 2011) (Message edited by jdugger on February 28, 2011) | ||
| Dirty_john |
Low rotating mass is critical, just think of the power required to accelerate a heavier wheel assembly from rest to 100 mph (assuming hah hah that the wheel is kept on the ground.) This low rotating mass is where the light Buell front wheel scores, an additional and equally critical benefit is low unsprung weight which really helps with suspension compliance for modern/lightweight sports bikes, In the seventies and eighties the bikes where so heavy the ratio between sprung and unsprung mass was higher and we needed gyroscopic stability on the road bikes of the time to dampen out the effects of the poor frames we had - heavy wheels equals more gyroscopic stability and the Japs hadn't heard of sports bikes then. I changed the heavy alloy wheels on my Suz GS750 for spoked wheels since at the time there were no tubeless tyres available, hence reducing rotating and unsprung mass. I have not had brake fade on my 1125R yet but have seen at least one 1125R cook its pads when ridden by one of the instructors at a Buell experience day in the UK in 2008, that was after a full day of being hammered around Mallory Park giving pillion rides to those brave enough. | ||
| Steve_a |
Lemonchilli is absolutely right that Japanese wheels have gotten a lot lighter. The XB/1125 front wheel is an old design, and Buell got a lot better at weight-optimized design after it was done -- and it remains a very good piece of work. It was made in a foundry that did (and still does) very good but not cutting-edge work. Suzuki has actually used forged aluminum wheels on some of the GSX-Rs. There's little doubt that improved material properties allow a forged wheel to be lighter than typical cast ones, and there are also Japanese casting practices superior to what Buell was using for the XB/1125 wheels. However, you do have to add all the parts at the front to see the difference, including extra brake lines, banjo bolts, spacers, pads, etc. No production front wheel/brake system was lighter than Buell's, and the ones that started to even come close cost more, sometimes very substantial amounts more. Keep in mind this same system was being fitted to $8000 XB9s, and at Buell's production scale we didn't have the luxury of a custom brake system for every machine. Also, Buell was just beginning to work on really light parts on the front end. The 1190RS front wheel derives from a design begun for racing. It represented the first substantial touching or consideration of the front wheel in 7 years. The 8-piston caliper is also a little overweight for what it is. It was originally designed to be a bolt-together caliper as stiff as a MotoGP monoblock. Then Nissin productionized the Buell design, adding substantial material and reducing the area available for airflow. The Nissin 8-piston is also a cast part, not forged as are many pure racing calipers. A race-only ZTL3 design was largely finished before Buell closed, substantially lighter, stiffer yet, with titanium pistons and with much more airflow area than with the production 8-piston. It was to be a forged/billet piece, and remained a bolt-together design only because it was hard enough to get Nissin to make it under any conditions, let alone add a difficult manufacturing step. The Erik Buell Racing caliper starts with a Nissin production 8-piston, and modifies it similarly to the pure race design. It loses some weight in the process. A few things to keep in mind: Fork legs with two brake mounts weigh more than legs with the single mount of the 1190RS. One brake line is lighter than two, as is one disk and one caliper. Honda and Suzuki are running lightweight 3.5mm disks on their open-class machines, and those disks are definitely not used for Superbike racing, though they'll hold up well for track days or club racing applications of those bikes. Racing disks are heavier -- go look at a Brembo race catalog, and you'll see 5mm and even 6mm steel disks for high-performance dual-disk applications. To sum up: the Japanese and Italian companies began to whittle away the Buell front wheel weight advantage, largely by optimizing individual parts beyond what Buell had done, and by using more expensive manufacturing processes. The 1190RS represents Erik Buell Racing re-establishing the weight gap by doing the same. The ZTL design, whatever it's eventually branded, has an inherent weight advantage over conventional dual disk designs. | ||
| Drawkward |
Steve, good insight. Weight saving aside, has the ZTL been proven to work as good as its heavier counterparts? And in your opinion, is a 3 or 4 pound weight savings a good trade off for inferior braking if that were the case? | ||
| Jdugger |
Drawk, "inferior" might be overstating it a touch. The actual braking action of the ZTL system I've found to be effective with the right pad and rotor selections. The bike *will* stop. It's more an issue of will the bike continue to stop application after application. I've had really just two key issues with the ZTL system in club-level racing and frequent track day use. 1. It's service prone. It wears pads, rotors, mounting hardware and requires caliper rebuilds at far faster rates than other systems I've used. 2. It's heat prone, so fade can (and will with the OEM stuff) be an issue later in a session or race if you are on a decent pace. We've kinda beat this one to death, and it's very fair to say there have been some significant upgrades to the state-of-the-art with ZTL, in particular around the rotors and mounting hardware, since Steve's comments on the one-off parts on Eslick's bike circa 2009. When it's working, I've not known the ZTL to have a problem slowing the bike. As for the unsprung weight comment, I will tell you as a novice racer it's my opinion it's really hard to feel (if I even do) the difference in 2.5 lbs savings using the Buell race wheel + Ti hardware vs. an OEM wheel, and the corresponding 3-4lb savings by using the rear race wheel + race rotor. Objectively, I am simply not consistent enough with my laptimes, even on a clean track, to really make a measure of the impact of OEM vs. -2lb front wheel. I'd say for everyone here except maybe an expert racer or two, something like 1psi of tire pressure or just simply rider weight is likely to make a larger impact on traction available than the unsprung weight advantage of a lighter wheel. And certainly the suspension system is dramatically more important. I think so much of this is really just mental masturbation. I'd be relatively surprised if any non-racer here could turn 10 laps in a row within the 2-3 seconds supposedly saved by ultra light wheels like the carbon fiber ones cited in Blake's argument about the importance of unsprung weight. What I'm saying is -- it's so difficult for an ordinary rider to be consistent within the window of benefit supposedly provided by these high tech aids on a bike that doesn't change at all, I don't see how it's going to be such an important impact on ordinary rider performance, and certainly on street level performance. It's not intuitive at all, but literally hundreds of track days have taught me that often I'm making these little "improvements" just because I want to. Because, I can get on the stock bike, or a bone stock Honda from 6 years ago, and sometimes go faster. My invitation to the track was centered around that... let these guys feel for themselves just how *little* a wheel swap does for the feel of the bike -- even when saving 5+ lbs of unsprung weight -- vs. something like tire pressure, their comfort on the track, sunlight vs. clouds, and so on. And, I'd planned to simply sit on pit wall and time them, so they can see the 5-10 second lap-to-lap variances they were getting, even within the same sessions on a bike that didn't change at all! It kinda comes back to that "it's all rider" comment. When you get to fast expert and AMA levels, sure, these little things make a difference. But, I'd bet none of us here are consistent enough lap to lap to even be able to accurately test the impact of a wheel swap between OEM and race wheels, and the unsprung "advantage" that goes with it. | ||
| Blake |
JD, I'm not trying to deflect or strawman you -- I'm trying to talk a little sense and reason into your belligerent fanboism that can't see any side other than the "buell must be better one." That's simple then; all you need to do is show how a heavier front wheel assembly is better than a lighter one. Not that you cannot tell the difference. That's a non-sequitur. You can put better tires on, but if you don't push hard enough to use the extra performance, you won't notice it. That doesn't make the tire not better. A lighter front wheel is better. Less unsprung weight is better. As Jens says, "what wins is better." Let's be clear. My view isn't that "Buell must be better." My view is that less unsprung weight is better. I'm still scratching my head wondering how anyone could argue against lighter being better on a sport bike. Not three years since ZTL introduction; it was introduced in 2003, so eight years? Correct. "When you consider the advancement from ZTL-1 to the current 1190RS system, all in just three short years" Also correct. From ZTL-1 to the 1190RS was a three year interval, okay maybe four years. ZTL-2 was introduced in 2008. It's now 2011. That is four years elapsed since the first revision to the system. A lot of advancement has hit the market in those three short years. See the new 1190RS for instance. B-bike? This is getting better all the time. I think it will take at least three or four full days at the track for me to be able to responsibly compare the effect of different wheels. (Message edited by Blake on March 01, 2011) | ||
| Jdugger |
> That's simple then; all you need to do is show how a heavier front wheel assembly is better than a lighter one. Blake, That's never been the nature of the debate and you know it. First it was heat, which you denied as the problem sighting some samples of success on the race track with the ZTL system. (Should we start citing examples of success of dual-disc systems as rebuttal?) Then it was the unsprung weight advantage, which I've argued (apparently unsuccessfully) isn't nearly as big a deal as you make it out to be. Then it was if Buell even retains an unsprung weight advantage, and I'll pull some weights for us this weekend so we can see what it is today for production bikes, and based on your knowledge of what the 1190rs front weighs vs. XB wheel, a darn good guess at what tomorrow's advantage will be as well. Now, it's just arguing if I think outright a lighter wheel isn't as good. I've NEVER said that. Of course lighter is generally better. I suggested it didn't matter, certainly not at yours or my skills levels, and certainly wasn't worth gaining as an advantage if dealing with brake fade is the trade-off. I'm actually flattered you consider me one to propose deflection and straw-man arguments, because you are the master of it. I tan in your sunlight from afar. > ZTL-2 was introduced in 2008 I thought it came out in 2006 with the XBRR. My mistake. > B-bike? This is getting better all the time. Yes. As it turns out many racers have two of the same bikes for parts symmetry, A vs B comparisons, and back-up. Had I not popped a collar bone, I would have been on mine this past weekend and this one up-coming enjoying it. If I thought you would take me up on it, I might just offer you 3 days on-track. Just be afraid of what you learn. Bring your OEM wheel, though. I want you to compare THAT to one of mine that's been upgraded. Now THAT's something you can tell the difference in. | ||
| Froggy |
Not to be a pain in the ass, but the XBRR had ZTL2 when it debuted in 2006. | ||
| Ridenusa4l |
froggy- i was thinking the EXACT same thing +10 Jake | ||
| Ratsmc |
Aren't you guys getting bored of this, yet? |
