| Author | Message | ||
     Jsg4dfan |
2008 XB12XT. I'm hoping to solve two aggravating issues with one step, if possible. If anyone has experience and/or advice with the following, I am all ears... Current setup: Stock handlebars, heavy HVMP bar ends. Issue number one: Vibration. Between 2000 and 3000 rpm, this thing is a jackhammer. Anywhere else on the tach is livable, but in that range, it is aggravating as hell. Aggravating enough I may sell it, because guess what rpm range in which I spend 80% of my riding time? It makes my XB9S feel like a sewing machine. The HVMP's helped, but they moved the sympathetic frequency a bit lower, and actually made it slightly worse in that particular range. Time saver - Yes, I have checked primary adjustment, and yes, I have searched and read several posts on the subject. Issue number two: This is not nearly as important, but it wouldn't bother me in the least if I could get the bars slightly closer. Slightly lower is okay, a little more sweep is preferable to less. Closer is my number one desire, but it takes a huge backseat to vibe level. Question 1) Those of you running 1 1/8" bars - did you notice a difference in vibration level and/or pattern? Question 2) Anyone running HVMP bar ends with the 1 1/8" bars have comments on the issue? Question 3) Anyone running 1 1/8" Raptor bend bars? If so, with which clamp adapter? How do they compare to the stock bars in bend and vibe level? Last question: Anybody want to buy an XT? | ||
| Tootal |
Have you checked the condition of the front motor mount? When that goes it will be a jack hammer! | ||
| Jsg4dfan |
I have - the gap is good. Can it be faulty if it still has a good gap? Also, my understanding is it will vibrate pretty much all the time if the front isolator is shot - am I mistaken? | ||
| Thumper1203 |
There are a few potential remedies you may try, such as filling your bars with lead shot, installing "vibranators" or a "bar snake", moving to lighter bar-ends than the hvmp's(the palmers, split to accept the handguards work well for me). Also a slightly loose primary chain will accentuate vibes, usually in the 35-4000 range though.. does your bike feel like it is going over railroad tracks, or "lumpy" upon deceleration?.. your isolator could still be on it's way out, even with visible air-gap.. A fresh, non-fatigued set of bars may help, along with new plugs and a proper tune. Also, are your tires balanced well? I use dyna-beads exclusively with great results and a glassy smooth ride. | ||
| Hughlysses |
Also check primary chain adjustment. A too-loose primary will increase vibration in that range. | ||
| Panhead_dan |
Just my opinion but if you make a habit of operating your engine at such low rpms, you are going to have much worse problems than a jackhammer. This engine was designed to be run at over 3000 rpms. Lugging it, especially under load is bad ju ju. More to your question- the front and rear motor mounts should be inspected. You will likely need to take them apart to do this. The bike shouldn't vibrate much as long as it's a bit above idle. By 2000 rpms or so it should be smoothing out. It should be very smooth at 2800 or so and higher rpms. | ||
| Jsg4dfan |
I was hoping someone would be able to comment on the extra stiffness of the 1 1/8" aluminum bars having an effect. | ||
| Panhead_dan |
Sorry to have not answered your question about the bars. It is unusual for this bike to need fat bars because of vibration. Down right unheard of. It is common for one of the engine mounts to be worn or broken. Just trying to help. | ||
| Spotts |
I'm running Buell CR upright bars, 1 1/8. Love the bend, but have not noticed any change in vibration patterns. But, I NEVER run extended distances under 3,000. Motor's just not in it's happy place. | ||
| Froggy |
There is not too much you can do to smooth it out below 3000rpm, its just the nature of the 12. An airbox kit with breather reroute and the EBR race ECM will help, as just like your 1125, a portion of the sub 3000 vibrations are due to the EPA. | ||
| Spacecapsule1 |
vibration started bothering me after several years. What i discovered is the gradual increase in vibration was a result of a decrease in the existence of a connecting rod bearing in my crankshaft.  yes the 1 1/8" bars helped. | ||
| Thumper1203 |
Allow me to venture a guess spacecapsule1.. yours was an 07'?  | ||
| Henshao |
"Just my opinion but if you make a habit of operating your engine at such low rpms, you are going to have much worse problems than a jackhammer. This engine was designed to be run at over 3000 rpms. Lugging it, especially under load is bad ju ju. More to your question- the front and rear motor mounts should be inspected. You will likely need to take them apart to do this. The bike shouldn't vibrate much as long as it's a bit above idle. By 2000 rpms or so it should be smoothing out. It should be very smooth at 2800 or so and higher rpms." Sorry but I have to disagree. I'm riding a 2001 M2 cyclone and I spend most of my time at 1800-2900 rpms. I agree with you in that it does get smoother and smoother around 2000rpm's plus but at the same time the bike should be operable above around 1600rpms. Take into consideration that these bikes 1)weigh very little 2)are geared very low and 3)have a truckload of torque. It takes almost deliberate effort to actually lug the engine on a 1203 Buell. Lugging the engine in my definition is a condition where the engine cannot gain speed effectively at any throttle position. I think from a volumetric efficiency standpoint, or specific fuel consumption standpoint, the engine might be best operated at 3000rpms especially with the stock cams. But that doesn't mean that we should throw out 1/2 of the operating range of the engine. If these bikes redlined at 15k rpms it might be true that you should try to stay above 3000rpms, but even the best among us are below a 7k redline. Another thing to bear in mind is I have big twin pulleys on my bike, it is geared 18% taller than a stock Cyclone and it has a much heavier pulley to boot. I'm still only lugging it at like 1400-1500rpms. I think something is wrong with the OP's bike. that is to say, it's broke. | ||
| Spacecapsule1 |
surprisingly enough, it was NOT an 07. it was an 08. | ||
| Thumper1203 |
Spacecapsule1, that IS surprising!.. was the root cause of the failure ever discovered or deduced? Henshao, good post, howsoever, there is an inherent primary imbalance in our v-twins that must be dealt with externally with rubber damping, cam timing, tuning etc. (Message edited by thumper1203 on January 20, 2013) | ||
| Mark_weiss |
One of my other bikes does have a 15k redline. That bike is best operated above 8k. My air-cooled BMWs redline at 7k and are best kept above 3.5k. Just the way most performance motors work. | ||
| Arcticktm |
I don't run much under 3k, so won't offer anything there. As for bars position, how about trying something like ROX risers with a low bar (unless you also want the extra height like I did)? thane you can get pull back and a wide range of adjustment. | ||
| Henshao |
I don't want to argue about little stuff so I'll try to say something helpful. The range in which an engine provides it's best performance will be determined by it's cam profile and on the sportser 'evo' engines there are only two valves per cylinder, meaning there is only one range in which the engine provides optimum efficiency. On racing motors peak torque will be at redline and down. But on modern production vehicles, especially cars but my Cyclone as well, the engine (in the interests of daily driveability) must sacrifice peak HP to provide much more torque down low where we need it more. The Uly I would especially expect to have grunt over screaming redline horsepower. Thumper1203 is right, however, in that this has only a cursory relevance to vibration because the isolators also only have a certain range in which they will work and that has different criteria like flywheel weight. By 2000rpms the vibrations should be gone on ANY Buell, though, for multiple reasons. The first being that Erik would have wanted a vibration-free bike for as much of the operating envelope as possible and we are talking about a small envelope here. Secondly, if the engine is designed to give it's best torque between say 1500 and 4000rpms, that's where you want to have the least amount of Vibration Noise and Harshness. | ||
| Conchop |
I had an issue with low speed vibration too. One thing I wish I would have tried is the Trojan spring loaded belt tensioner. I'm a big guy so I think my isolators were stretched and inducing some additional vibes. When it comes to handlebars, I found that adjusting them in a forward position, the effects of the vibrations were somehow directed upward, and less intrusive. | ||
| Jsg4dfan |
Out of desperation, I tried the following: 1) Removed the heavy bar ends 2) Loosened the primary chain by about a fret. Whole. Different. Bike. Yes, you read correctly - I LOOSENED the tension on the primary. On my bike, this worked, and worked well. I'm still going to add some 1 1/8' bars, and an XB9 primary. If I were made of money, I'd find an 08+ XB9 engine, put a big bore kit in it, and put that in my Uly, but that's just me. Anyone who owns both a 9 and a 12 probably understands why I feel that way. | ||
| Etennuly |
Another thing to look at is operating it below 2500 in cooler weather can be wetting your plugs with too much fuel. Like everyone has said these engines have a happy spot for cruising. Mine will run smoothly at 2500 to 3000 on level or down hill, but if running up hill it does much better to grab a gear. I had a city-X 9er. The Uly's taller gear has never been an issue for me. It did take some time to get used to taking off up hill two up. Off roading and trail riding can be a bitch. Given that, the original clutch is still strong at 60,000 miles. I would only go to the 9 gear if I had a sixth over drive gear. | ||
| Henshao |
Maybe my bike just has more torque than everyone else's. I often upshift at 2500rpms. | ||
| Kag |
I put heavy bar weights on and filled the bars. I also switched to gel palmed gloves. All of these helped but but I still have vibes at times. | ||
| Conchop |
How loose is your primary??? I suppose the chain flopping around might counter balance an offset crank. I know on my old shovel heads, the oldsters always left some slop in their adjustments. 3/8's and 1/4 seemed snug - are you about a half inch or so??? | ||
| Thumpthump |
I do know that changing to a modified exhaust will change your vibrations, but not necessarily for the better. |
