Twitchy Front on 1200GS

[fisherman]

I have 2500 mi on my new GS and it's not very stable at interstate speeds. (trucks will really make it jump around) Would an investment in a set of Wilbur shocks make much difference for this specific problem? Thanks.....

[* SHAG *]

There are threads around here or other sites about this issue! Some have changed front & rear suspension settings with good results! I noticed a little twitching compared to my 1150 at first, but when loaded for a trip & after 15k miles, it's no issue for me!

[Jim VonBaden]

www.advrider.com always has a couple threads going on in the G-spot section about this.

 

I had it mildly at first, but taking the front down to the second lowest preload, and the rear up just past half way virtually eliminated it.

 

Jim

[ShovelStrokeEd]

The best thing you can do is to train yourself to use only a minimal contact with the bars. Instead of rolling your hands around the grips, try resting them on top. A throttle meister might be some help here. I can't remember if GS's have cruise but I think not.

 

The wake turbulance from a big truck can be pretty fierce. If you allow it to act on your shoulders and arms and transmit that motion to the bars the bike is gonna get twitchy. I think the 12GS is better than the 1150/1100 in terms of windshield but a wind screen that is layed back a bit more towards the rider seems to help here as well.

[Ken H.]

I think everyone notices it at first on the 12GS. They are a bit more "twitchy" than other BMW bikes. I suspect some of it has to do with the shorter rake and trail.

 

At any rate some of the solution, as Jim mentioned, is to soften the front suspension a bit and firm up the rear more. Be very consonant of not running too high of air pressure in the front.

 

Some of the solution, as Ed mentioned, is to be sure you are using correct loose arms, elbows bent and down, etc. handling of the bars.

 

I found my changing the angle of the factory wind screen to much steeper (using Tobinators) and taking off the hand guards helped a bit.

 

But in the end the best answer is to just get use to it. Realize that even though the front may move about a bit more than you may be use to, especially around trucks and such, in reality it's not going anywhere. The bike's not about to bolt for the ditch or anything. Relax and enjoy the ride.

[MattS]

Didn't know I have an adjustable front preload ... I'm going to the garage to play with that. Edit: Okay, it was two notches up from softest, we'll see if softest makes a difference.

 

I had some serious issues a few weeks back running late for an appointment and playing city games on the country interstate. Any hard acceleration (lifting the front wheel) and especially when running the white line immediately next to tractor-trailers would see the front end wash around -- loose arms or tight, good posture or bad.

 

The solution is many, many small feedbacks, kind of like your hands on a steering wheel when the going gets hairy ... ya just gotta keep making adjustments to keep the line straight. Certainly not confidence-inspiring, but the takeaway is that the bike wasn't really made for certain kinds of shenanigans as much as it was for others.

[steveknapp]

Any hard acceleration (lifting the front wheel) and especially when running the white line immediately next to tractor-trailers would see the front end wash around -- loose arms or tight, good posture or bad.

 

I'm missing how you expect the front end not to be loose if it's off the farkin ground.

[fisherman]

Thanks all. Consensus seems to be making the rear shock heavier and the front lighter. I'll try that and let you know how it works. It's sure is cheaper than Wilbur shocks.

[CMWingfield]

Not to cause alarm, but I didn't see anyone mentioning those pinchbolts on the front fork. I don't know if loose ones could contribute to "twitchy" front end action, but checking them couldn't hurt. When I checked mine two were very loose.....

 

Just a paranoid thought.....

Mike

[ShovelStrokeEd]

I'm at a bit of a loss here. Softer front, firmer rear is going to reduce both rake and trail, making the bike MORE sensitve to steering inputs, not less.

[MattS]

I'm at a bit of a loss here.

Me too ... did a 6-mile Italian tuneup about an hour ago and the arm wiggle with the settings mentioned above was extreme. Fun, but I could see where it would get weird.

[roadscholar]

I won't discount suspension settings being a culprit and I have'nt adjusted mine(yet). But I think aerodynamics may play a part as well and I believe Ed and Ken H. touched on it. I rode a friend's '06 last week with an Aeroflow windshield on the interstate with trucks at elevated speed and it felt very stable. Conversely, my bike has been fairly twitchy in the same conditions with the orig. windshield in any position or a +5 Cee Bailey.

[Ken H.]

I'm at a bit of a loss here. Softer front, firmer rear is going to reduce both rake and trail, making the bike MORE sensitve to steering inputs, not less.

I hear you Ed, but for those of us with the 12GS that have been playing with this issue for awhile, that seems to be the case.

 

'course maybe we're all just imagining it in the same direction...

[Jim VonBaden]

I'm at a bit of a loss here. Softer front, firmer rear is going to reduce both rake and trail, making the bike MORE sensitve to steering inputs, not less.

I hear you Ed, but for those of us with the 12GS that have been playing with this issue for awhile, that seems to be the case.

 

'course maybe we're all just imagining it in the same direction...

 

Also, it seems to have more of a positive effect on 12GS's with heavier riders. The lightweight riders sometimes report that doing the oposite sometimes helps.

 

It is very true, though, that the front shock is stiffer than it needs to be, even on its lowest setting, and the rear is slightly undersprung.

 

Jim

 

PS I don't even notice the twitcy feeling anymore. But when I rode a friend's 11GS recently, I did notice howmuch heavier the steering was. No doubt it felt a bit more stable.

[Marty Hill]

Wow! All this time I thought the twitch was from me shaking cuz I was going over 50 mph on the slab. Seems very fast to me.

[Ken H.]

Wow! All this time I thought the twitch was from me shaking cuz I was going over 50 mph on the slab. Seems very fast to me.

Marty we're talking about the twitch in the 12GS's front end, not that other "twitch" of yours!

[hophead]

"I'm at a bit of a loss here. Softer front, firmer rear is going to reduce both rake and trail, making the bike MORE sensitve to steering inputs, not less. "

 

A lot of people do not understand the language of suspension and consequently make wrong adjustments to their bike's setup based on other's advice---and then make their ride even worse. I am a big fan of setting proper rider sag and leaving the rebound and compression settings at factory recommendations before thoroughly making adjustments to suit one's ride. BTW Shovelstrokes posts are always a must read for me.

[steve.foote]

BTW Shovelstrokes posts are always a must read for me.

 

And that would be because the "Shovel" is usually right.

 

All this talk about suspension adjustments still overlooks one of the easiest and least expensive modifications. Rider posture.

 

Leaning slightly forward to remove shoulder-to-arm bias to the bars makes a significant difference. If you are either leaning on or hanging off the bars, turbulence from your exposed shoulders will be transmitted to the bars causing the front end to feel shakey.

 

Give it a try next time you're in a turbulant situation. Lean forward and take all pressure off the bars. I'll bet the bike settles down instantly.

[roadscholar]

Good point, which would help explain the rock solid stability I experienced with the Aeroflow equipped GS. Took the turbulent air off the shoulders.

[jimswms]

Good point, which would help explain the rock solid stability I experienced with the Aeroflow equipped GS. Took the turbulent air off the shoulders.

 

Probably, the same thing, but, for me, I had a problem with the twitchiness, and the GIVI screen solved it FOR ME. I think what was happening is that the 12GS is substantially lighter in the front than my old bike was. Because of this, I was putting too much pressure on the bars, basically fighting the wind blast. Once I got less wind blast, from the larger screen, I instinctively loosened up on the bars and the twitchiness went away. works for me.

[sjn7708]

I have Wilbers on my GS -2" from stock and havent noticed any twitching. I also have a cee bailey windscreen. I didnt ride it too much before I got the Wilbers put on so I cant say whether it twitched more before the Wilbers, but its bone solid now.

[NakedRider]

A agree with most posts about the help from suspension changes but, to me, the biggest issue is still the super high wind shield.

 

Why is a GS so easy to turn compared to other bikes? It's because it's very tall and you have huge leverage with those wide bars. Push it around your garage. Then push a bike with clip-ons. Much easier to push the GS...right? Better leverage.

 

Same thing with the windshield. It's way up there with all that leverage on the bike. It's very easy for the wind to move this bike. Go to any dealer and look at the GS parked next to anything else. It's like a two-story building. The wind is going to move it around more. Period.

 

You have the windshield coupled with the "beak" taking all that wind, sometimes sidways, and it moves the bike more than other bikes.

 

I've noticed a difference twice before installing my Ohlins. First I got one of those carbon fibre "beaks" and believe it or not you could really feel a difference in front end stability. Then I REMOVED the windshield. I took more wind but the bike was MUCH more stable. Eventually I really wanted a little wind protection so I cut down the windshield and raked it back with tobinators. MAJOR difference from stock.

 

Remember this is a VERY tall bike. In some respects it's like being easier push over on a bar stool than if you were sitting on a dinning room chair.

 

My .02

[PaulW42]

Whatever the reasons, I found that turning up the preload significantly and tweaking the damping slightly on the rear end (the front was left on factory recommendations) TRANSFORMED the handling on my 1200GS. And I tried a lot of posture, hand/arm input and screen position experimentation before that; none of which effected such a change.

 

In all the bikes I've owned, I've never been a great one for changing the suspension settings (too lazy ) but it was certainly worth it in this case.

 

A thought: I wonder if the preload increase jacks the back up enough to change the pattern of airflow over the beak and screen; perhaps giving more "downforce" on the front end?

 

Paul

[NakedRider]

 

A thought: I wonder if the preload increase jacks the back up enough to change the pattern of airflow over the beak and screen; perhaps giving more "downforce" on the front end?

 

Paul

 

Could be part of it. I do think it's multiple factors.

[Jim VonBaden]

Leaning slightly forward to remove shoulder-to-arm bias to the bars makes a significant difference. If you are either leaning on or hanging off the bars, turbulence from your exposed shoulders will be transmitted to the bars causing the front end to feel shakey.

 

...

 

Which probably explains my general lack of issues with the "twitchy" feel of the bike. I did notice it a little at first, but the riding position I usually assume is more of a sport riding position. I have the balls of my feet on the pegs, slide forward on the seat a bit, straight back, and light hands on the bars.

 

BTW 5'8", 28" inseam, and right at 200 pounds. Just for reference. I ride quite fast according to my friends, very sporty (some say squidly ), and often at higher speeds.

 

Jim

[mistercindy]

I'd just echo many of the posts already here.

 

- First, recognize that you're on a bike that sits very high off the ground with a dry weight of only 440 pounds. The nature of your beast will be to get impacted by turbulence more than you would on an RT, ST, GT, LT, etc...

 

- Soften up the front pre-load, and firm up the back. That did a lot for my ride.

 

- Lighter grip on the bars. With the lighter grip, you may get whacked by turbulence, but it won't impact the bike. A lot of the perceived twitchiness isn't the bike so much as its your upper arms and shoulders getting hit, and your grip transfering it to the bike.

 

- Try to sit more "sport like" and let the shield to its work. Those of us who are all torso find this a bit harder to do.

 

I also installed a Laminar Lip. I'm 6'0" with only a 30" inseam, so I sit very tall in the saddle with my shoulders and torso way above the stock shield. I put the Lip on so it is 4" above the top of the stock shield and it helped the turbulence a great deal. I still get some, but not nearly as much. Still, the 12GS isn't the slab machine I'd like, and after this season I may invest in an Aeroflow.