| Author | Message | ||
     Redstar11 |
I have raised this question up in the Desert Riders area of the board. Basically, I bought my 04 Buell XB12s a few months back looking for something different from the Japanese bikes I own (04 GSXR 1000, 02 RC-51). After the bike being down for the past few months, I finally took it for the hardest ride since I have owned it. The 80 mile route consists of very fast sweeping turns. Some of these turns took everything the Buell could muster at 130+ mph or 5th gear nearing red-line. The bike felt fairly stable in the corners, the roads there are in pretty good shape. However, when exiting, and holding the throttle wide open, I experienced headshake on a regular basis. Even on straight aways nearing 130mph, the headshake was very apparent. I have set the sag on my bike around 30mm, and the damper adjusters are set most of the way out for a slightly softer street ride. I have perfectly balanced Pirelli Diablo Corsa's running 36 PSI. I was wondering how many others are having the same problems when pushing the limits of this motorcycle. I am definately in line to purchase a steering damper for it, hoping that will cure most of the problem. Suggestions, thoughts, comments? | ||
| Daves |
You need to adjust your suspension according to the owners manual or the more aggressive settings here on Badweb. With it set up the way you have it it is no wonder it doesn't handle correctly. | ||
| G4string |
I noticed that w/ my bike as well. I took it into the shop for some new shoes last week. After their test ride they claim that the steering head bearings are bad a/o loose. I was at the same point you were. I was ready to fork out 350 for a damper. Check the bearings before you buy a dampner. I havent fixed the bearings yet so I have no idea how much it is going to cost. Just some food for thought. FWIW, my bike is a 2003 XB9SL w/ 3500 miles. | ||
| Diablobrian |
36 psi is a little high for the diablo corsas unless you're riding 2 up, and then I run 34 front and 36 rear. Solo I run 32/34. For a track day 30/30. firm up your damping a little. the majority of adjustment is in the last 2 turns or so. Also make sure your steering head bearings are set right. Proper sag settings should have you set better than the factory charts. See if that helps (Message edited by diablobrian on June 18, 2006) | ||
| Daves |
Yes, check the neck bearings too. The other thing to consider is at 130 mph on a S, you may be giving input to the handlebars without realizing it? | ||
| Redstar11 |
Christ, steering head bearings going out after 3500 miles? I'll have to check mine after I get my bike back up on the rack. DaveS, you say it's "no wonder" my bike is handling the way it does because of the way I have my suspension set up? Why? I have my sag (spring preload) set for a good ball park on a sport chassis. Next time I ride im going to turn in the rebound dampers a little bit to see if that helps, provided the head bearings are in good shape. When I ride, I actually have a fairly light grip on the bars. At speed on the S, I duck as low as I can go, and grip the frame with my knees hard. I don't think my input is inducing the shake. | ||
| Gentleman_jon |
Kind of hard to diagnose without knowing your weight, but it sounds like you don't have any damping at all, this can lead to instability. I am not sure if the 30mm sag is correct either. You might want to look at the Shawn Higbee aggressive suspension settings for your weight. Here they are in the knowledge vault. http://www.badweatherbikers.com/buell/messages/3842/107725.html?1147822998 Steering bearing probably are not shot, but they do have a tendency to loosen up. Tighten as per the procedure outlined in the Shop Manual. If you are planning on riding at the speeds you mention, a steering damper is always a good idea. The LSL model for Buell is available from Daves, or Al at American Sport bike. Personally, I prefer to have one mounted, and I don't do any 130 mph cornering.  | ||
| Redstar11 |
I am 165 lbs, 5' 11". The screw damping adjusters are usually for low speed suspension action. The internal valving is what really controls the broad spectrum of suspension action. Thats why I'm somewhat skeptical of everybody just yelling out that my adjusters are way off and causing this problem. I understand that there is no magic number for suspension set-up, which is why I wanted to get everybody else's experiences and suggestions from the board. | ||
| Kurosawa |
http://www2.ee.ic.ac.uk/cap/cappp/projects/2/files/simosthesis.pdf Here ya go. Let us all know what it means after you've wrapped your brain around it. | ||
| Diablobrian |
Take a look at the higbee settings for your damping and lower your tire pressure a bit. give it a try before dismissing it out of hand. These bikes are VERY sensitive to suspension changes. The internal valving does set a large portion if your suspensions' action, but that does not mean the damping and rebound adjusters are superfluous. It can make a day and night difference on an xb just being a 1/2 turn off on a couple of adjustments. Many here have learned that the hard way. Write down your current settings, try these settings, and then you can return to your old settings if you want to when you get back from a test run. Note the recommendation of 1/4 to 1/2 turn change to soften ride. Higbee has an ENORMOUS number of miles test riding Buells.  | ||
| Redstar11 |
Ok, next time I get a chacne to put my bike on the lift, steering head bearings will be examined first and foremost. I will set the Buell up to Higbee's agressive riding numbers and compare them to my current set-up with sag measurements included. Final step will be another hard, high speed run to evaluate the differences. | ||
| Diablobrian |
sounds like a plan, what do you have to lose? | ||
| M1combat |
It was probably wallowing with little damping. Also... I haven't ridden an "S" but I would imagine that just the wind at 130 would put some input in the bars. Also... What tires? If they are the 207's they only work decently when you hang off... Hanging off of an "S" at 130 would almost certainly add input... | ||
| Diablobrian |
He said Diablo Corsas  , but at 36psi. | ||
| Redstar11 |
I have felt wallowing from a lack of suspension damping before. Ive ridden plenty of bikes with blown fork seals. This was not wallowing. For my next ride, I'll drop my PSI down to 34 in front, 36 in back. | ||
| Daves |
Redstar, I did not mean to offend you. The XBs are very sensitive to correct settings and yours sound like they are way off that's all I meant by the "no wonder" comment. I also agree that you probably do not need new neck bearings but as mentioned they do tend to loosen. I have to re-tighten the ones on my wifes 9S with only 170 miles on it. It may or may not be that? You also mention that the bike was "down" for the past few months. Was it something wrong with the bike? | ||
| M1combat |
34/36 would be a little better. You're light so I might choose 33/35 or 32.5/34.5. That said... I've never been that light so take it with a grain of salt . I also ride fairly far forward... so... I don't know what'll work for you. The XB's are sensitve to suspension adjustments. I'm not sure that it's the chassis that is sensitive or if the forks have a wide range of adjustment which makes the knobs sensitive. Either way... a little goes a long ways. Wallowing from the rear I meant. The XB isn't meant to have a "plush" ride  . From what I hear you should be happy with the Higbee settings. I've never used them though, so I can't really comment on them. (Message edited by M1Combat on June 18, 2006) | ||
| Sgthigg |
Is you front wheel balancing weight on the rotor side? If not put it there, it tells you that too in the serv manual. I had the same thing sord of. | ||
| Lenb |
When I let go of the bars on my XB12R at say 60-80kph (35-50mph) my bars wiggle continuously from side to side. Nothing serious, but I just wanted to know if this is normal? (on other sportbikes I have owned the bars have been rock steady). Is it just a result of the XB's ultra short wheelbase? btw - my suspension is set up for my weight, steering head isn't loose, my tyres aren't worn and the pressures are correct. Oh and please no cracks about "why would you let go of the bars?" Sometimes when coasting down from speed it feels good to sit up and and have a stretch. (Message edited by lenb on June 19, 2006) | ||
| Buelltroll |
"Is you front wheel balancing weight on the rotor side? If not put it there, it tells you that too in the serv manual. I had the same thing sord of." THAT sir is incorrect. I just had tires mounted and balanced today at Auburn HD the tech said the last time they sent him to school that it has been changed. The weights go OPPOSITE of the rotor now. |
