| Author |
Message |
    
Trxtodd
| | Posted on Thursday, September 08, 2005 - 03:39 pm: | 
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Hi everyone, I need some ideas here to what you think is causing a recent problem with my '05 firebolt XB12R. If I am at cruising speed or any speed for that matter and let go of the bars, the bars start to shake real fast back and forth. I think that it is a steering stem bearing that went bad, but I am not sure. Please any help would be greatly appreciated.. And I am going to go to the dealer this weekend. Thanks Todd |
M1combat
| | Posted on Thursday, September 08, 2005 - 03:53 pm: |
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Check the tire pressure and check for cupping or feathering of the tire. What tires?
My first guess is that you need a new set of tires. It very well could be other things. Be careful. |
Tank_bueller
| | Posted on Thursday, September 08, 2005 - 03:58 pm: |
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It could possibly be a tire issue...??
I have a similar problem. the more the tire wears the worse the shake seems to get.(really not that bad, honestly) Had the steering bearings checked and all was good there.
I seem to remember other posts of folks changing tires, and the problem went away.
...Or it could be the steering head bearings!!??
just my $.02
tank
(M1 beat me to it....slow typer)
(Message edited by tank_bueller on September 08, 2005) |
Stealthxb
| | Posted on Thursday, September 08, 2005 - 04:00 pm: |
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raise front wheel and torque steering head to spec |
Buell12hundo
| | Posted on Thursday, September 08, 2005 - 04:22 pm: |
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check the tire for your weights...had an r1 and it did the same thing untill I got the tire balanced |
Tpoppa
| | Posted on Thursday, September 08, 2005 - 04:28 pm: |
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That does NOT sound like a steering head bearing.
What are you front and rear preload settings? and what tires are you running?
It sounds like your suspension settings are too aggressive. Increasing the rear preload or decreasing the front preload will make steering more sensitive. Too much of either/both can result in head shake, especially during hard acceleration.
Different rear tires with taller profiles can also cause this. |
Rsh
| | Posted on Thursday, September 08, 2005 - 04:45 pm: |
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When you let go of the bars at cruising speed you are decelerating. The XB V-twin has a high amount of engine breaking that causes a change in geometry which reduces the rake and trail enough to cause the instability or head shake in this case. For an experiment try shifting into fifth gear and do the same thing the shake will be reduced or eliminated because the engine breaking effect will somewhat be nullified. |
M1combat
| | Posted on Thursday, September 08, 2005 - 04:55 pm: |
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"The XB V-twin has a high amount of engine breaking"
Not really. There's less engine braking in a 12R than a 600 race replica. Whether one should still call that a "lot" or not I don't know, but I know it's a good deal less than ?most? sport bikes. |
Fl_billy
| | Posted on Thursday, September 08, 2005 - 05:41 pm: |
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Had the same thing on 04 12R - minor bar wiggle when I would let go between 60-50 mph. Once I changed the tires to new Dunlop 208's, problem was gone completely. I also agree with M1 on the engine braking - the 12R has next to none compared to other sport twins and even I4 liter bikes. |
Tpoppa
| | Posted on Thursday, September 08, 2005 - 05:45 pm: |
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True. XB's do not have a lot of engine breaking, compared to other sportbikes, even some other v-twin sportbikes. |
Trxtodd
| | Posted on Thursday, September 08, 2005 - 05:51 pm: |
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OK here goes...this problem just started about 2 days ago. The tires are stock, with no noticeable scalloping. There is still a fair amount of tread left too. My suspension has never been touched since the factory. My bike has 2,600 miles on the clock. Thanks for the help guys...but still confused. |
Trxtodd
| | Posted on Thursday, September 08, 2005 - 05:57 pm: |
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also it doesn't matter what gear i am in, 1st or 5th, and not to sound like a jackass, but when i let go of the bars I can't be accelerating cause my hand is off the throttle. Thanks again. Todd |
M1combat
| | Posted on Thursday, September 08, 2005 - 06:06 pm: |
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Set the suspension by the manual. Check your tire pressures. |
Rsh
| | Posted on Thursday, September 08, 2005 - 06:25 pm: |
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Trxtodd,
Not to sound like a jackass, I typed decelerate in my post, you read accelerate. |
Wyckedflesh
| | Posted on Thursday, September 08, 2005 - 06:37 pm: |
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Todd, I highly suggest, though it seems to have been discounted, to follow the service manual instructions for adjusting the head bearing tension.
StealthXB is on the money to an issue that is just starting. |
Buellin_ri
| | Posted on Thursday, September 08, 2005 - 07:23 pm: |
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tend to agree with rsh myself. has to do with the rake and trail on sport bikes (had a ninja do the same thing new tires or old). Put a dampner on it. Thats what I did. Thats why the sell em. |
Steve_uk
| | Posted on Thursday, September 08, 2005 - 07:36 pm: |
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Have you tried keeping your hands on the 'bars? 
Seriously, I had a couple of Jap bikes in the 80s that did just this if I took my hands off at around 30mph.. I remember reading of other bikes doing it too. Can't say I've noticed my XB doing it though. |
Oneway
| | Posted on Thursday, September 08, 2005 - 07:46 pm: |
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i would check the weights |
Lenny
| | Posted on Thursday, September 08, 2005 - 08:01 pm: |
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Had a headshake problem on my XB12s going around corners at speed, turned out to be steering head bearings. Raise the front end off the ground and check how loose the bearings are. Also check for grease leaking out the bottom of the steering head. Follow the service manual instructions for checking the head bearing tension. Check the profile of your tire and air pressure. |
M1combat
| | Posted on Thursday, September 08, 2005 - 08:04 pm: |
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The majority of XB's do NOT do this unless there's something wrong.
A steering damper is a band-aid and is NOT the right solution. That's NOT why they sell steering dampers... and it's damper... Not dampner (which would be dampener anyway, but that's a different subject entirely, we aren't asking you to dump a bucket of water on your head).
I think that a shotgun approach is in order to fix the issue (note that I didn't say band-aid the issue).
New tires.
Steering head bearings.
Tire pressure.
Setup defined by the manual. |
Az_m2
| | Posted on Thursday, September 08, 2005 - 08:24 pm: |
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My brand new 12x is doing that ever so slightly, I'm going to play with the suspension setting. Currently at factory recommended. |
Buell12hundo
| | Posted on Friday, September 09, 2005 - 09:38 am: |
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keep it simple, start at the rim and check for the weights, then move on to the head bearings and so on ......
thats what I'd do n e way |
Cruisin
| | Posted on Friday, September 09, 2005 - 10:14 am: |
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Yup...usually the steering head bearings. Prime example - mine did it slightly between 50 and 60 when I let go...
Over the winter when I was fixing a few parts I loosened that up, and when I didn't have my torque wrench handy just snugged it up. Well now it would do it any any speed above 30 and violently if I let go. I was redoing something else and while I had the front end up in the air I torqued it properly. Almost ALL shake went away. The little bit I had went away when I replaced the front tire (stock tire with 7k miles on it). Now I can let go at any speed with no worries.
So check that steering head bearing! |
Pwnzor
| | Posted on Friday, September 09, 2005 - 10:20 am: |
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I'd say check to make sure your balancing weights are still on the wheel. Beyond that, ditch the dunlops. Get any tire that doesnt have a straight groove running down the middle of the tread.
As for engine braking, I haven't seen anyone mention what gear they are in or how fast they are going. Engine braking is subjective and depends on both of those things. |
Xb9
| | Posted on Friday, September 09, 2005 - 10:55 am: |
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Tires - for sure.
Get rid of those crap oem tires and put some Pirelli Diablo or Michlin Pilot Powers on there.
(Message edited by xb9 on September 09, 2005) |
Buellin_ri
| | Posted on Friday, September 09, 2005 - 08:17 pm: |
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no need to get nasty M1, it was just my 2 cents. |
Cruisin
| | Posted on Friday, September 09, 2005 - 09:23 pm: |
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I don't think he was getting nasty...he was just making it clear that although a damper may make the problem unnoticable, it does not fix it.
I think people tend to do it as a band aid when the problem needs to be fixed, as he said.
I have a steering damper on my Firebolt, but it's not because of the shake I had.
So to anybody that has a head shake like this, follow Don's list to FIX the issue. |
Buellin_ri
| | Posted on Friday, September 09, 2005 - 09:37 pm: |
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i was talking about the whole spelling jab it was just a typo no need to degrade somebody because they mis-spelled something. |
Pwnzor
| | Posted on Friday, September 09, 2005 - 10:04 pm: |
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yeah that was a little out of line in my opinion. |
Heads
| | Posted on Saturday, September 10, 2005 - 02:14 am: |
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Buellin_ri, we knew what you was talking about |
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