| Author | Message | ||
     Diablo1 |
A lot of the pre-production reviews have complained of engine vibration above 5,000 rpm. This is surprising since the older design Rotax V60 (990) is a smooth engine, and the 1125 has a wider V angle with an additional balance shaft. Did you characterize and compare vibration using accelerometers with other V twins during development? Is the perceived vibration of the 1125 a result of fueling issues, engine mounting, or some other issue that can be fixed before production? | ||
| Thespive |
Or is it something a rider coming from and XB would never notice and the journalists are just being nitpicky? --Sean | ||
| Paintballtommy |
either way they are comparing it to the competition and it could turn off some potential customers who dont like that idea | ||
| Jlnance |
Or is it something a rider coming from and XB would never notice and the journalists are just being nitpicky? I rode the bike at VIR. The vibes are completely different than those from the XB. The 1125 does not shake at idle. As you bring the RPM up, the bars get buzzy. I don't know exactly where it happens, it was my first track day, and I was attempting not to die.  The 5000 rpm range sounds about right, it may be even higher. They don't buzz at low rpm. I did find it fatiguing. I'm assuming Buell will address this somehow. | ||
| Vagelis46 |
I found the vibrations&buzz produced from the GSXR1000 K7, to the pegs and bars, very annoying. I rode a GSXR a few weeks ago and did not like the high frequency vibrations produced by the high revving engine. My XB12R feels actually smoother just after 2000 rpm I guess that there is price to pay with these hi-performance and hi-revving engines. Sometimes people make comments about a bike's vibrations, but when I personally ride it I feel a different story. I personally found the TLS and RSV engines, both very smooth. Some others really thought that the vibrations very really too much. But these people had IL4s. I really find the high frequency vibrations from IL4s very annoying. So talking about the 1125R vibrations is a very odjective subject. Test ride it, and then we will see. | ||
| José_quiñones |
I rode it at VIR. I loved the bike but the most shocking, disturbing thing about the bike is the annoying high rpm vibration. I rode several different bikes to see if they all behaved the same and they did. It is really buzzy at 8000 rpm and above, at 8000 the tach needle is a blur in the area around 8000. It would kill the idea of this engine in a SportTourer. Being a track day and because the speedos were covered, I do not know if the bike buzzes you at highway+ speeds (80 mph in sixth gear). I spoke with one of the Buell engineers at the track day and he is aware of it, but thought that in normal street riding most people will not notice it. He mentioned that the engine shakes more than their design said it should and they are looking in to it. Other than that, the engine character is very similar to the 990 Rotax used by Aprilia/Can Am. Anybody that has ridden one of those and then rode an 1125 would immediately notice the family resemblance. The best way I can describe the engine as I rode it at VIR is coarse. Hopefully the production bikes will be smoother. (Message edited by josé_quiñones on September 23, 2007) | ||
| Bearly |
I will test drive it, but I think that might be it for me. I wanted to replace my Uly on long 1 or two day trips. I guess we will see. | ||
| Paintballtommy |
things like this could make or break a bike in my eyes just simply writing it off as most people wont notice it is not acceptable. but as you said i have complete faith that they are looking into it and it will be addressed before production. | ||
| Vagelis46 |
"Other than that, the engine character is very similar to the 990 Rotax used by Aprilia/Can Am." Are the vibrations felt on the 1125R the same as in RSV ???? If this is the case, I think that there is no real problem, since I consider the RSV a smooth bike. | ||
| Rubberdown |
I rode two at VIR. The first had strong vibes through the pegs at high revs. I found it annoying. The second bike was much smoother. | ||
| Blake |
I'm having trouble reconciling the following:
If you have to rev the thing to over 8000 rpm to get into irritating engine vibe territory, and the redline is at 10,500 rpm, how can that be a problem for a sport touring application?  With a reported top speed in high gear of around 170 mph, at 8 grand in top gear the bike is going to be moving at over 130 mph. How many sport tourers are riding around for any prolonged interval at 130+ mph? | ||
| Blake |
That said, it sounds like the engine could use another iteration of balancing. | ||
| Paintballtommy |
i agree | ||
| Ratbuell |
I don't know about the bikes the way they were set up for VIR, but the map we had at Pocono was smooth and solid. There was a bit of vibration above 8k, but nothing that struck me as "excessive". For the rev/MPH reference chart to begin, we were told unofficially that 10,500 (cutout) in third is approximately 114mph. If anyone wants to experiment from there as to gear relations, rev drops, etc., there it is. | ||
| Gentleman_jon |
I found the vibration in the handlebars to be VERY annoying at around 10,000 rpm at the Pocono demo track day. People were moving rather rapidly, so I did not spend too much time looking at the tach, and the wide torque curve meant that one could shift before the vibration got too bad without losing much speed, if any. Still, I hope this is something that can be remedied. | ||
| Jimidan |
That said, it sounds like the engine could use another iteration of balancing. I would have thought that it would have been smoother with the experience of Rotax developing somewhat similar V-twin engines (and not wanting to "repeat the errors of the Aprilia engine"), and with Buell's mode analysis used to predict vibratory modes in the structures and surfaces, and Buell's emphasis on testing that all resulted in the 72 degree mill with 3 (count 'em) balancers. Even the rocking-couple was to be balanced as well, as Buell wanted "a bike to ride all day". This engine was supposed to be smooth with the vibration "quelled at the source", allowing the engine to be mounted directly to the chassis with mounting points chosen "that would avoid undesirable chassis-oscillation frequencies". The reports that the bike shakes at high RPMs even after all of these extensive and expensive efforts, leads me to the question of just how smooth can a 72 degree engine run? Regarding the vibrations, the 72 degree engine is STILL a compromise to the 90 degree V-twin (there is a reason why Ducati still builds 90 degree motors), as they have apparently done whatever can be done in trying to balance it? Maybe this is all that can be done within the limitations of the relatively narrow V. I have faith that if it can be further refined it will, but when? I might just hold off on my purchase (and hold onto my Ducati 996R) for another year to let them work the bugs out. My Duck has no bugs, 'cept on the windscreen, which are easy to remove. | ||
| Bobup |
come on guys....vibrations that are unreasonable at 10K rpms ????????? how long will you be holding the throtle WFO? most of the time you will be in the 3K-6K range cruising along or rolling on and off the gas....NOT WFO | ||
| Bonjoxb12s |
Lets all remember that Eric was quoted as saying this was a bike designed for the STREET..... the track is a good first glimpse of this great bike, but not the ideal situation. I highly doubt anyone will be buzzing 114 mph in 3rd gear on a hwy... if so you wont have a license for long. Take your 8k rpm and bring it down a notch and I'll bet you see some great attributes from the 1125R. | ||
| Paintballtommy |
thats not the point... the fact of the matter is that with state of the art technology and 3 ballancer shafts youd expect it to be smooth all the way through the rev range. jose says its really buzzy above 8 grand. ANONY can you clear this up and let us know what is being done to correct it? | ||
| Jaimec |
Every counter-balanced bike I've ever ridden had a "sweet spot" where there was no vibration whatsoever and then it would get more pronounced as revs went up. This isn't a Buell issue, it's just the nature of the beast. Obviously they've tuned the balancers for where most of us will spend 98% of our time when riding it. Some of us, however, like raising the picking of nits to an art form... | ||
| Paintballtommy |
dont mean to sound like im nit picking i just want the product to be as best as it can be right out of the gate. you and i both know that the press is gonna tear this bike apart as soon as it goes into production. i just dont want to see them having anything to muck about. | ||
| Jimidan |
10,000 RPMs? A lot of the pre-production reviews have complained of engine vibration above 5,000 rpm. Then some complained about it above 8,000 RPMs. With a 10,500 redline, there will be lots of time spent in those ranges, especially at a track day. True enough, with the torque that this engine produces, one would not have to dwell in those ranges much while riding on the street. The question is does the Buell's competition have excessive engine vibes in the above 5K range? The Duck does not. | ||
| Bonjoxb12s |
With everyone testing this bike, you have a lot of independent opinions. Some say above 5k, some say 8k.... some say it's smooth. Best thing you can do is wait and ride one yourself and form your own opinion. | ||
| Jimidan |
That man, Jose` sez: I rode it at VIR. I loved the bike but the most shocking, disturbing thing about the bike is the annoying high rpm vibration. I rode several different bikes to see if they all behaved the same and they did. It is really buzzy at 8000 rpm and above, at 8000 the tach needle is a blur in the area around 8000. It would kill the idea of this engine in a SportTourer. This man is not raising the "picking of nits to an art form...", as you need to keep in mind that he is not only an S3 Buell owner/rider, but also a V-rod owner/rider, and an engineer. I would be curious on Jose`'s comparison of the vibes or the 60 degree Porsche based engine in his V-rod to that of the 72 degree Rotax based engine in the 1125R. On the face of it, the 60 degree mill would have more primary vibes to counterbalance, and it has fewer balance shafts to accomplish it. If Jose` is startled by the 1125R's vibes, I would give that observation some merit. What sayeth ye, Jose`? | ||
| Spike |
I don't intend to speak for Jose*, the 1125R(s) I rode at VIR vibrated quite a bit more than what I remember of the V-rod. There was so much vibration that the tach needle was literally a blur spanning ~500rpm. It was actually quite bothersome. However, when I did my 2nd session on a different 1125R the vibration didn't really stand out. I'm really not sure if I was just immune to it by the time I went out for the 2nd session or if the 2nd bike was actually better. I do know that on my 2nd session on the 1125R I was thinking less about the bike and more about the track. *Sorry about the accent mark, I tried alt+0233 and it just wouldn't come up. I then tried turning on the international keyboard in Windows so I could use '+e, but it still wouldn't come up. I even tried cut and pasting it from your username, but it just came up as a question mark. | ||
| Jlnance |
I'm really not sure if I was just immune to it by the time I went out for the 2nd session or if the 2nd bike was actually better. It's quite possible that not all those bikes are identical. I don't know if Buell did a run just for the Journalists/Track Days, but if I was making test bikes, I'd make a couple, look for problems, change the design make a few more. | ||
| Blake |
The balancers may just need tweaked a bit. It is to be expected. Analysis is only as good at the accuracy of its assumptions and boundary conditions. Crankshaft bearings supported by a film of oil along with oil coated components (added mass/inertial), not to mention the temperature conditions of the engine are impossible to model perfectly for dynamic analysis, thus you create an engine and actually run it and test it and make adjustments to it based on real world performance. Judiciously adding or subtracting a few grams from counterbalancers is not a big deal. It is bewildering how some folks imagine that the first cut at a new engine should be perfectly balanced cause that is what the engineering analysis predicts. If that were true, we wouldn't call it "engineering", we'd just call it "science." | ||
| Bonjoxb12s |
+1 on Blakes comment | ||
| Xb9 |
My GUESS is that Buell might have different balance shaft variations to test among all the pre-production units - hence the reports that this one vibrated more than that one, etc. I'm confident that Rotax will apply their experience with previous engines that they have developed and apply that knowledge to optimize the balancing for the Buell production units. | ||
| Bob_thompson |
At my age I have ridden many shakers, vibrators and thumpers and I think it is part of the whole good experience of motorcycling. The old Triumphs and BSA's would deaden my hand in 10 miles. The UJM buzz would also do the same at a different frequency and the HD's just need a little extra loctite here and there. All give a feel for your particular bike. The worst bike for pure feel was riding was a BMW K model. Could not feel anything and it was like riding a Cadillac auto. No feeling at all. I like some "feel" to my bike as it gives it personally. I can feel my M2 and I like it. The 1125 will have "personality". |
