Stability issue / wobbly

[herwawan]

Hey!

The work on my XB12Scg (2005) keeps going and there's one big thing left that is bothering me, I can't figure out. Simply put, the bike feels instable over a certain speed (around 75/80mph).

The first thing I noticed a while ago is that over 30/40mph, if you slightly shake the handle bar from one hand to another, the bike will wobble for as long as you shake it - not in a way that can make me fall or lose control though. It's not going to keep going once you stop shaking it. With that in mind, I just assumed it was because of the sharp angle of the front fork, but after talking with other Buell enthusiasts, turns out it isn't really normal.

Recently, I feel like over a certain speed, the bike becomes a little bit unstable and it doesn't feel that much safe. Over 75/80, it's hard to explain but it just feels "light" and a bit shaky.

Now, the steering head bearing has been replaced less than 1000 miles ago and the wheels bearings have been changed last week with the hope of fixing it (thanks to Cooter!). Although it felt like it in the beginning, turns out it didn't entirely.

So I'm a but confused as to where to look. Putting the conversation over the forum may help bring more ideas and maybe one of you even has experienced that before, who knows!

Thanks

Max.

 

[Silverrider]

The neck bearings should have taken care of ur wobble, Who did the work on ur bike ? What was used for the neck bearing Balls or taper ? What torque is being used?

 

[rchuff]

What tires are you running (New or old) and are they balanced right? I have had tires make the bike unstable. Even a new tire could do it.

 

[wickedchop]

Right on Ricky. I have had old tires wreak havoc. Tires can have snapped belts inside and you wouldn't even know by looking at them, you sure can tell by riding on them. Silver brought up great questions as well. Report back with your findings

 

[midway]

Not riding 'Cock Sure' uneasy feeling but you don't know what it is .... keep looking. Mine was rear wheel bearings but I see you got that checked off.

 

[Silverrider]

Riding position could be a key factor also.

 

[rchuff]

Here is some advice STOP shaking the bars. Just ride the bike normal and go from there. If you did steering head bearings and wheel bearings the only other thing would be tires.

 

[Silverrider]

Listen to all the above ^^^^^^^^^^^^^^^^^^^^^^^

 

[herwawan]

Great feedback! Here are my answers:

The neck bearings should have taken care of ur wobble, Who did the work on ur bike ? What was used for the neck bearing Balls or taper ? What torque is being used?

Being a critical part, it was handled by a Buell specialist at a local HD shop (Bartels'). The bike was not even turning correctly before the change, it truly made a complete difference on the riding experience. The stock parts were used (not the balls).

What tires are you running (New or old) and are they balanced right? I have had tires make the bike unstable. Even a new tire could do it.

The tires (Dunlop Sportmax Roadsmart II) are from 02/2016 and have 3,000 miles on them. I did notice I lost my rear balancing weight recently, but can't say for sure it has had any impact. I'll take care of that soon - but the front one is still in place.

As for the riding position, I'm pretty comfortable on the bike ( = relaxed) although I'm a tad tall for it (6"2). I have the taller seat (same as the XB9SX), the suspension is set to the higher setting and with all that, it's definitely okay and comfy.

 

[Silverrider]

Balls are stock, I upgraded to the taper bearings in the neck. IMO all bikes should have Taper Bearing. You might want to tighten the neck up just a bit .

 

[Cooter]

Hey Herawan, good idea to ask the Buell brain trust here

I want you to come ride Stella and then the XB9SX back-to-back. Stella is completely stable and my XB9 does what I think you are describing. Both have new wheel and neck bearings. The only difference between the two is the XB9 has a front tire thats squared off.
Feels unstable at speed like you say. Also in a corner it feels like it falls into the corner then you need to 'catch it' to keep it upright.

I'm leaning to new-front-tire. Leaning... get it???? PUUUUUUNNNNNNNNN!!!!!!

 

[njloco]

You so, so ,so,, funny ^^^^^^^^^^^^^^^^^ !

 

[toolmaker98]

This may sound dumb and too easy. I have heard if the tire is mounted backwards that it will cause a wobble. So might want to check tire rotation.

 

[rchuff]

Hey Herawan, good idea to ask the Buell brain trust here

I want you to come ride Stella and then the XB9SX back-to-back. Stella is completely stable and my XB9 does what I think you are describing. Both have new wheel and neck bearings. The only difference between the two is the XB9 has a front tire thats squared off.
Feels unstable at speed like you say. Also in a corner it feels like it falls into the corner then you need to 'catch it' to keep it upright.

I'm leaning to new-front-tire. Leaning... get it???? PUUUUUUNNNNNNNNN!!!!!!

And such a brain he is!!!!!:applause:

 

[John Vreede]

Definitely agree with new tires.
My bike was handling like a pig. Had to push it into a corner and then hold it so it didn't turn in too much like Cooter said.
Tried servicing the suspension ($1200US) for no real improvement.
Found a big part was rusty steering head bearings which meant was hard to initiate a turn.
Soon as bearings were change it was obvious that had been masking too low tire pressure (was running ~35psi). Was much better after pumping to 38fr-40r but still not right.
Tires were worn, back 3/4 front ~1/2, but not flattened profile, they were nice and round. I've been around bikes long enough that they didn't seem to me to be a problem. A knowledgeable mechanic friend, who does a lot of race setups, said "Put new Metzler Z8's front and back and pump tire to 38-40psi fr & 40-42psi r and I guarantee it'll be fixed". He was right. Its higher pressure than most people run but with new rubber at that pressure, the bike steers neutral now, but I can feel when the tire pressure drops even 3psi.
I've never had a bike as sensitive to tire condition and pressure as the Buell, and I know its not just mine; a Firebolt and an SS I rode were the same. The Firebolt was brand new demo bike in 2003 that steered so weird I didn't buy it because of that; the dealer told me later the tires weren't pumped enough. The '08 SS was worse than mine was, even with 40f & 42r psi in the tires. His tires didn't look too bad either but at 8000mi were probably still the originals 10yrs later. I bet the bike would have been transformed with new tires.
If either of the tires has flats just go buy new ones. If (like I did) you think they're OK, try pumping the tires harder and see if it gets better.
If it does, go buy a matched set of new tires. Any good brand of sport compound will be ok I think, but the Metzler Z8's work well on my Uly - jv

 

[herwawan]

I want you to come ride Stella and then the XB9SX back-to-back. Stella is completely stable and my XB9 does what I think you are describing. Both have new wheel and neck bearings. The only difference between the two is the XB9 has a front tire thats squared off.
Feels unstable at speed like you say. Also in a corner it feels like it falls into the corner then you need to 'catch it' to keep it upright.

I'm leaning to new-front-tire. Leaning... get it???? PUUUUUUNNNNNNNNN!!!!!!

It took me awhile to get it OMG haha yeah we really need to schedule some back-to-back experiences!

This may sound dumb and too easy. I have heard if the tire is mounted backwards that it will cause a wobble. So might want to check tire rotation.

I double checked this morning, it's all good! Now, I realized the back tire isn't factory size, (190/50ZR17 / Factory is 180/55ZR17). Funny.

Definitely agree with new tires.
My bike was handling like a pig. Had to push it into a corner and then hold it so it didn't turn in too much like Cooter said.
(...)
If either of the tires has flats just go buy new ones. If (like I did) you think they're OK, try pumping the tires harder and see if it gets better.
If it does, go buy a matched set of new tires. Any good brand of sport compound will be ok I think, but the Metzler Z8's work well on my Uly - jv

I don't really have this issue in corner at all to be honest, or at least nothing I noticed. But starts to feel like there isn't much other options outside of new tires. I'll look at it - maybe there's a good deal out there in the next months.

It looks like the bike went down multiple times in its life (both sides, the frame is dented on the left, the header is scratch on the right, there are marks of fall on the footpegs, plastic and handlebars. I had this weird moment where I wondered if a fall could alter the handling of the bike - but truth is I have no idea if that's just stupid to even think about it. Just throwing that out there haha

 

[Cooter]

A fall wouldn't really do it. They are tough bastards. But a wreck certainly could:eek-new:

I would assume Mitsu would have caught any funkiness when he did the steering neck bearings.

 

[Provy]

I would make sure the suspension is set up correctly (for you), and then start looking at tires pretty hard.

 

[optomist]

All, I strongly suggest the following: Most of the time any weirdness with the handling is tire related. Been there, done that. I can not believe how some of you are thinking--For God's sake there are only two wheels and your life is hanging in the balance. I mean riding is marginal at best so get your damned head on straight. If you can't afford a new set of skins then you should just park the bike until you can.

People often say how economical it is to ride a motor bike--Well, I call BS on that. First cost are high, insurance is high and tires are expensive. I figure, on average, .06>.10/MILE

 

[optomist]

cont'd
to keep your bike on the road with decent rubber. It is just as stupid running on old tires as it is to run without a decent helmet and riding gear. Get it together and get out there!

Opto