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Blake
| | Posted on Sunday, June 08, 2003 - 10:58 pm: | 
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Steve,
What Rick said. Please keep your hands on the bars at 70 mph.
edited by blake on June 08, 2003 |
Skully
| | Posted on Monday, June 09, 2003 - 08:17 am: |
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"If you take your hands off the bars on the XB9 series at 70 or so, the front end will start to develop a slow motion tank slapper."
Steveford - are you absolutely sure the suspension is set up correctly for your weight and the tires have the recommended air pressure? Are you carrying a load that could affect these factory settings?
Keith
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Mikej
| | Posted on Monday, June 09, 2003 - 09:35 am: |
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Do you have a throttle lock? If not then when you remove your hands the throttle closes and upsets the geometry, and with no input nor control from your hands on the handlebars you might be inputting minor signals to the bike via your feet, legs, or butt that might be causing the slow motion tank slapper.
I don't know what exactly a slow motion tank slapper is, but at 70 mph if your forks turn lock to lock there ain't nothing slow motion about it. 
I ain't no expert, and I don't claim to be, I just type a lot at times. YMMV.
quote:Occupation: Buell sales
State/Province: PA
Bike Model: (Hidden)
Model Year: (Hidden)
All the above assumes you are riding a production bike. If you just happen to be on a pre-production bike then this probably isn't the best place to be asking these question. While we'd probably all love to know all about the test Mule bikes there are probably better avenues to post inquiries about them. Just curious why you have your bike model hidden? If you're in sales and have multiple bikes to choose from then just state "Varies based on availability". But, oh well, so it goes, no biggie.
Have a nice day. Someone once said the best way to cure a tank slapper was to do a wheelie, but I have no documented proof of this concept.
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Steveford
| | Posted on Monday, June 09, 2003 - 06:23 pm: |
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I don't know why anything's hidden; I currently own a 65 Norton Atlas, two 850 Commandos, a 79 Bonnie, an 85 Guzzi Le Mans, a Firebolt and I'm paying off an 02 X1W White Lightning.
Some of the Buell guys know me from when I was a Guzzi dealer or through the powder coating - the shop's name was Parts-Is-Parts.
My 85 Le Mans nearly killed me one day up in NY State when I nailed the throttle on this one long downhill section, hit a bump at 90+ and it went into a vicious tank slapper. Didn't crash but it really put a scare into me.
Ever since then, I've been concerned with wobbles so always run an unfamiliar bike up to 70 or 100 MPH or so, take my hands off the bars and then coast down to 40 to see what it does. If it's going to wobble, I want to know in advance when I'm prepared for it, NOT in the middle of a high speed corner!
For the Buells that I've ridden, the tube frame ones track rock solid hands off while the new ones all start fluttering at 60 to 70 MPH. If you leave your hands off, the flutter will progress into a tank slapper.
Once you pop on a steering damper, you can run a Firebolt or Lightning up to 100 and then coast hands-off down to 40 with everything the way it should be.
As for the Guzzi, I did everything and the wobble kept returning: Forcella Italia front end, better steering damper, 18" Astralite rims front and back, fork sliders line bored and a fork brace made up by Albert Bold (MV Agusta/machinist wizard) and when I called up Albert to tell him that it still wobbled, he mentioned a lathe he once had that would develop a harmonic imbalance at a given RPM and walk it's way across the floor.
His suggestion was a different tire altogether so I tried a Michilin radial up front and it hasn't wobbled since.
Perhaps Michilins will do the trick on the Firebolt so I'll try them with the damper temporarily removed although I suspect the 21 degree fork rake is the culprit.
It isn't my intention to start a big handling controversy - the bike didn't come with a damper but it should have so I popped one on and everything's fine. |
Mikej
| | Posted on Tuesday, June 10, 2003 - 08:21 am: |
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Thanks for the followup and expansion on the dialog. Nice collection of bikes too. 
The steering geometry and wheelbase is what put me off the 'bolt. It's fine for what it is and does very well at what it does. It is funny though how two supposedly comparable tires can have such different effects on some bikes. |
Skully
| | Posted on Tuesday, June 10, 2003 - 08:32 am: |
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"It is funny though how two supposedly comparable tires can have such different effects on some bikes."
Changing to a different tire with a different mass and/or circumference can have a huge effect on a light, steep front end like the XBs. It changes the dynamics of the system.
I have a race-prepped Honda F3 with a steering damper. It still startles me how much I can change the way the bike turns simply by a slight change in the front tire (120/60 to a 120/70).
Keith |
Dynarider
| | Posted on Tuesday, June 10, 2003 - 08:36 am: |
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Change the tires for "normal" ones, none of that lightweight crap & your handling problems will be history. I have it on very good authority that this is proven & works. |
Dynarider
| | Posted on Tuesday, June 10, 2003 - 08:38 am: |
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BTW Mike, the last thing you are thinking about when you go into a tank slapper is popping a wheelie. I had that one last year & all I can say is HOLY SHIT!!! It happens so fast & comes out of nowhere. My arms still hurt just thinking about all the wrestling I did with it & still got thrown off. |
Buellistic
| | Posted on Tuesday, June 10, 2003 - 09:36 am: |
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BUELLers:
If do the "DEATH GRIP" on the handlebars it will
cause you to go into a "SPEEDWOBBLE"... You must relax!!!
In buelling
LaFayette |
Mikej
| | Posted on Tuesday, June 10, 2003 - 10:35 am: |
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Dyna,
Yeah, I know, 'twas one of them there sarcastic comments that gets passed around the pits sometimes. Hey! I just realized, I didn't get to look at your bike when you were up. Well flubberized floorboards and all that, guess I'll just have to wait to see it in person some other time. |
Blake
| | Posted on Tuesday, June 10, 2003 - 04:30 pm: |
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Dyna,
Exactly what handling problems are you talking about? They guy's front end wobbles a little bit when he takes his hands of the bars going 70mph. Sorry, but in my book that is not a handling problem and nothing that suggests any corrective action beyond checking steering head/bearings, tire pressure, and sag settings. You are making a problem where none exists. Keep your hands on the bars at speed ferchrisakes. |
Dynarider
| | Posted on Tuesday, June 10, 2003 - 04:41 pm: |
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I am not saying youy should ride no handed, but the bike also shouldnt go into a tank slapper when you release the grips.
And a number of folks have mentioned a weaving, wobble, instability, whatever you want to call it at higher speeds..im not saying 70mph is a high speed either. One of our own posters here who is a Buell tech & attending training in Milwaukee learned while in training that if you swap out the tires this instability will go away. The tires on the bike were designed for lightweight & ease of turning but they arent the greatest for high speeds. Its a simple & cheap fix for a problem that not everyone has, but for those that do its a lot cheaper than a steering stabilizer. |
Blake
| | Posted on Tuesday, June 10, 2003 - 04:51 pm: |
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Keith (Skully),
What you gotta realize is that going from a 70 to a 60 series front tire or vice versa is not a "slight" change. It results in a 12mm (10% of 120mm width) change in front axle height, nearly half an inch. Just raising the forks 6mm makes a significant difference in handling on many bikes.
Dyna,
Steve sounds like he knows very well what he is doing, and I can appreciate his concern. However, I've not heard a single report elsewhere implying that the XB9's need a steering damper. You'd think the moto press would have picked up on that, instead they exclaim how rock solid stable the bike is.
Steve,
You may be treating a symptom, with the problem not being inherrent in the design. To assert that the XB9's all need steering dampers is contrary to everything else I've seen/heard on the subject. It would be interesting to know the details for your specific case...
1. rider weight
2. sag settings (front and rear)
3. tire pressures
4. tire wear/mileage
5. front wheel weights/balancing
6. tire brand/model |
Steveford
| | Posted on Tuesday, June 10, 2003 - 10:20 pm: |
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Gentlemen,
Yes, I do look for wobbles and keeping the pressure from your hands on the Firebolt's bars will keep it from happening. If it does anything weird when my hands are removed, though, it needs fixing as that's just not right. One tank slapper was more than enough and I'll never be caught unawares again.
I'm not saying that the Buells are prone to tank slappers under normal conditions but if they will go into one with no hands on the bars, I am not willing to risk one when I momentarily run amuck.
The steering stem bearings were first torqued to Buell's workshop spec (wobble with hands removed) and then done 5 ft/lbs over before I chickened out as I don't want to damage the frame.
My weight goes from 160-170 lbs, all of the suspension settings are per factory recommendations in the owner's manual, the wobble tests were made at between 600-900 miles when I finally fitted a damper (decided at 130 MPH that it would be prudent to back off on the gas and call Storz on Monday morning), the tires are the stock ones which, oddly enough, have their yellow balance dots in the wrong place on EVERY Firebolt and Lightning I've seen. Remounting and rebalancing the tires has no effect nor does replacing the wheel bearings to the Taiwanese upgrade.
Tire pressure has varied between 36/36 and 36/38.
Everyone who owns one of these can certainly do their own no hands deceleration test on a clear section of straight road and see what happens.
The four that I've tried it on have all done it.
One of my buddies races one and his comment was, "Every Firebolt that races has a steering damper as you can't have a 21 degree fork angle and stability (w/o one). Mine wobbled through Turn whatever at Daytona for the first three laps until I could reach up and turn the damper up three clicks".
Here's an odd one: at the Buell sales school they handed out cards for the recommended suspension settings for all of the XB models (all models take the same settings which were per the Firebolt) yet the Lightning and the Firebolt owner's and shop manuals call for settings unique to each model.
So, which is correct?
Perhaps a factory suspension guru could twiddle the bikes to perfection but a steering damper set on the lightest setting has made my bike handle better than anything else I've owned or ridden.
Here's a perfect example: dodged a dead squirrel while heeled over cresting a hill with a blind, left hand exit (camber? taking a hard left at top of hill)at about 65 this evening which I would have squished and then skidded off of the road on my Guzzi. Done in by rodent entrails...
No headshake, no shudder, no nothing, just oh shit, flick, flick, phew that was close, maybe I should slow down a little. The new Buells are just phenomenal motorcycles.
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Timbo
| | Posted on Tuesday, June 10, 2003 - 10:55 pm: |
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Hmmmm,
I've encountered lots of different situations/conditions since getting my 'Bolt but have yet to feel anything even closely resemble a woble let alone a tank slapper.
The bike is rock solid. I mean, if anything, it's almost scary how confidence inspiring it is.
I've hit uneven pavement at speed with the bike leaned way over and thought "OH $#1t, this is gonna be interesting", only to have the bike take it in stride like nothing was even there.
To me the bike is amazing, and continues to impress me the more I push it.
Shakes?! Well, I do like the mint Oreo cookie type
Timbo |
Blake
| | Posted on Wednesday, June 11, 2003 - 03:27 am: |
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Steve,
Now that I think of it, I believe Keith (Skully) advised that his XB9S' front end would wobble a little if he let go of the bars.
Virtually all motorcycle road racers use steering dampers.
You say your sag is within spec, but what is it? |
Skully
| | Posted on Wednesday, June 11, 2003 - 08:26 am: |
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"Here's an odd one: at the Buell sales school they handed out cards for the recommended suspension settings for all of the XB models (all models take the same settings which were per the Firebolt) yet the Lightning and the Firebolt owner's and shop manuals call for settings unique to each model."
This does not surprise me as the seating/weight distribution is different between the two models.
Now that I think of it, I believe Keith (Skully) advised that his XB9S' front end would wobble a little if he let go of the bars."
I don't recall ever having said that. The bike has been unflappable so far.
Virtually all motorcycle road racers use steering dampers.
True, that has been my observation as well. However, most of the bikes were are referring to have had the front forks raised altering the stock bike's steering geometry (rake and trail).
Keith
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Blake
| | Posted on Wednesday, June 11, 2003 - 08:54 am: |
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What was I thinking of... you said something about the handling when you first started getting some miles on the Lightning... or is my mind going... what the heck were we talking about again?
I hadn't noticed raised forks on the newer models at the track. I'll have to do a quick confirmation check next race weekend. |
Bud
| | Posted on Wednesday, June 11, 2003 - 09:16 am: |
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My bike wobbles at 124 m/h when I hid bumps in the road, 
The wobble stops when the front wheel is back on the road
Suspension preload rear pos.6 front 3 rings
Compression front 0.5 turn rebound 0.5 turn
Rear the same
Tire pres 36/38
Almost forgot driver weight 15 stone
Gr,m
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Skully
| | Posted on Wednesday, June 11, 2003 - 01:36 pm: |
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"What you gotta realize is that going from a 70 to a 60 series front tire or vice versa is not a "slight" change. It results in a 12mm (10% of 120mm width) change in front axle height, nearly half an inch. Just raising the forks 6mm makes a significant difference in handling on many bikes."
How right you are Mr. Blake. However, what you gotta remember is, that at least in my case, there was a corresponding change of size in the rear tire as well.
The resulting overall change in axle height at my front wheel (Honda F3) is 0.236" or 6mm. The handling was not drastically changed, but it was noticeable. The bike does turn in faster and with less effort with the smaller front tire.
BTW, I found a Fox shock manual on-line. The shock on my bike does have ride height adjustment.
Now I'll have to see if there is any adjustment left...
Keith
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Steveford
| | Posted on Thursday, June 12, 2003 - 11:55 am: |
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The wobble is cured.
Prepped a new Firebolt yesterday and they torqued the steering stem to 40 ft./lbs at the factory SO torqued our demo Lightning to 45, dropped the shock preload to it's lowest setting which made the bike steady hands-off at 100 but it would still flutter at 60.
By increasing the fork preload 4 flats, the bike is now steady hands-off from 100 down to 40.
Still keeping the steering dampers on the bikes but thanks for making me actually think a bit more about the suspension set up.
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Anonymous
| | Posted on Monday, June 16, 2003 - 08:18 pm: |
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Quote: oddly enough, have their yellow balance dots in the wrong place on EVERY Firebolt and Lightning I've seen.
Sounds like you better read the service manual.
Define "wrong place"... |
Darthane
| | Posted on Monday, June 16, 2003 - 10:24 pm: |
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Quote: oddly enough, have their yellow balance dots in the wrong place on EVERY Firebolt and Lightning I've seen.
Sounds like you better read the service manual.
Define "wrong place"... <~~Anonymous
Yep...spoke to a tech the other day who informed me that the valve stems are NOT necessarily the heavy spots on the XB wheels. I personally mounted and balanced a front tire Saturday and discovered that the heavy spot on the wheel itself was about 1/4 around from the valve stem on my wheel (mysteriously, though, this spot did not coincide with the paint mark that was supposedly the mark of the wheel's heavy spot...could the fact that my wheel is now out of round have altered this or was it just plain wrong?). Once mounted, though, the heavy spot was at the valve stem.
Bryan |
Skully
| | Posted on Tuesday, July 01, 2003 - 01:32 pm: |
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"My 85 Le Mans nearly killed me one day up in NY State when I nailed the throttle on this one long downhill section, hit a bump at 90+ and it went into a vicious tank slapper. Didn't crash but it really put a scare into me.
Ever since then, I've been concerned with wobbles so always run an unfamiliar bike up to 70 or 100 MPH or so, take my hands off the bars and then coast down to 40 to see what it does. If it's going to wobble, I want to know in advance when I'm prepared for it, NOT in the middle of a high speed corner!
For the Buells that I've ridden, the tube frame ones track rock solid hands off while the new ones all start fluttering at 60 to 70 MPH. If you leave your hands off, the flutter will progress into a tank slapper."
Steveford,
I've tried to replicate the hands-off "fluttering" you describe above with my '03 XB9S with no luck at all. I let go of the handlebars at 80 mph and coasted own to approximately 40 mph with nothing happening at all. I've tried it with cold tires; I've tried it with hot tires. Absolutely nothing.
The little XB so far has been completely unflappable whether accelerating/decelerating in a straight line, in a curve, on rough roads, etc.
Darthane,
The tire changing instructions I have say to remove the old tire and all wheel weights and then determine the heavy spot on the wheel. Then the tire should be mounted with the paint dot coinciding with the previously identified heavy spot on the wheel.
Now, the wheel/tire assembly should be balanced per standard procedure. This should result in the smallest amount of weight being added to the wheel for balance.
Keith
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Darthane
| | Posted on Tuesday, July 01, 2003 - 02:25 pm: |
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Agreed - exactly what I did. It only took 1/2oz to balance it...the damned thing had 1 1/4 on it before, in two different spots! |
Steveford
| | Posted on Tuesday, July 01, 2003 - 09:03 pm: |
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I don't wish to beat a dead horse but I rode a brand new Firebolt today that had a fluttering front end so after making sure that the steering stem bearings were tight (they were), increasing the front fork preload two full revolutions took care of it.
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Blake
| | Posted on Wednesday, July 02, 2003 - 03:45 am: |
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Steve may have his own personal flutter inducing effect. LOL! Actually that is not as silly as it sounds. Aerodynamics of riding apparel and even the rider can make a difference. Might also be related to the Firebolt's fairing? Who knows. I wanna ride a Firebolt!  |
Steveford
| | Posted on Wednesday, July 02, 2003 - 06:34 am: |
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It might be due to the road cone epoxied onto my AGV. Safety first! |
Rex
| | Posted on Wednesday, July 02, 2003 - 05:46 pm: |
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I had a Suzuki 550 Three Cylinder and my Honda CBX wobble if you took your hands off of the bars...You could take your hands off of the bars, and the front end would start to wobble slowly , then it would work up to a vibrating back and forth that if you didn't take hold, the bike would have crashed. I had them checked, and nothing was wrong.
My buell M-2 is flawless. You can take your hands off and ride without hands as long as you want. M-2 Buell, Full of Torque, Great sound, priceless! Thanks Erik! REX |
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