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I am the new owner of an '03 12GT with 5,000 miles. Previously rode an '02 R1100S Prep. I really like the GT... the power, the ABS/cruise/heat/etc.

However, I have noticed that the front end seems to wander or move a bit, not the result of steering inputs, at least as I can tell. Seems to happen most often between 60-80 mph on open road. Pavement doesn't seem to be the issue. Tires are in good shape with less than 1,000 miles.

Any advice as to what may cause the front end wander/feel light?

RYP
 

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RYP said:
I am the new owner of an '03 12GT with 5,000 miles. Previously rode an '02 R1100S Prep. I really like the GT... the power, the ABS/cruise/heat/etc.

However, I have noticed that the front end seems to wander or move a bit, not the result of steering inputs, at least as I can tell. Seems to happen most often between 60-80 mph on open road. Pavement doesn't seem to be the issue. Tires are in good shape with less than 1,000 miles.

Any advice as to what may cause the front end wander/feel light?

RYP
Are you goosing it during roll-on acceleration? That thing has a torquey 130 hp to play with. :D
 

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Those tyres look less than average, and while having not covered many km's they may be old all the same. The only thing between your ride and the road are the rubber hoops - spend the cash and buy some new tyres. I have run Michelins for the last 6 years - Pilot road 2CT on the rear and a Power up front and have been very happy. Now if you really want it to handle, get yourself a set of Ohlins....
BTW looking at the photos again, the calipers are embossed with BMW - not so on the 2001 model which I believe has Brembo on them.
 

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Discussion Starter #4
Seems to happen at a constant speed. While I realize that I am working with 130+ hp, my previous bike had 90+ and was a good bit lighter, so I don't believe that throttle movement is having an affect.
 

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flyingkiwi said:
Those tyres look less than average, and while having not covered many km's they may be old all the same. The only thing between your ride and the road are the rubber hoops - spend the cash and buy some new tyres. I have run Michelins for the last 6 years - Pilot road 2CT on the rear and a Power up front and have been very happy. Now if you really want it to handle, get yourself a set of Ohlins....
BTW looking at the photos again, the calipers are embossed with BMW - not so on the 2001 model which I believe has Brembo on them.
New Perelli Corsa rubber was put on this past August when the dealer did the 20000 KM service. No problems there. Yeah, I hear you about Ohlins... once the rear shock dies I will go the Ohlins route. Apparently I got "Sport Suspension" as a MSRP option. Not sure how good it is and how well it will hold up. The rear seems compliant.
 

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RYP said:
Seems to happen at a constant speed. While I realize that I am working with 130+ hp, my previous bike had 90+ and was a good bit lighter, so I don't believe that throttle movement is having an affect.
Your front shock may be prematurely pooched. Also check the play on the front bearings. At 5000 km, both the shock and bearings should be perfectly fine.
 

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Don't notice float at that speed with my k13gt but sure gets light when running to redline in 1st. Feels like I am just barely touching ground.
 

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RYP, these bikes are rock solid at speed even in wind.

When you say the word “wander” do you mean like go everywhere, “wander all over the place.”?

If you mean wander to the right, as in drifts to the right, we all know about that. !

These bikes do as a rule drift “wander” to the right.
Depending on what tires you use it can be very slight to extreme.

Other items look at for wandering, not just a drift to right;
What brand and type tire is on the bike?
Tire pressure, Frt 38 to 40 PSI, Rear 42 PSI
Is swing arm tight, no play to very little play?
Was front tire/wheel installed on the axle shaft to forks correctly?
There is a spacer between the rear wheel and the centering spigot “hub” is it in place?
Are all wheels secured “bolts torque” correctly?
Has this bike been wrecked, is alignment correct?

Hope that helps.

Barry
 

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RYP,
Do the check on tightness of things. check for wheel play etc. Steering head, steering damper, My first guess would be rear tire pressure.
If nothing else, we might could go for a short ride, and you try my 03 RS for comparison.

It can also be a combination of tires and road surface which I have noticed at times.

I have noticed this wandering but only when the pavement is not smooth but having a variety of ridges running along it from top coat resurfacing.

Good luck with this.

Stephen
 

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My front end also wanders, 2003 K1200RS, but only when I am buffeted in the wake of semi trailers. It makes it very interesting when you have to pass 2 or 3 of them at the same time.....! Meeting semis on the highway the bike may give a couple light head shakes.Downshifting certainly helps, you have to get those horses to push you out of it.7,000 RPM+ in 3rd or 4th....Yippeee, I love it.... :)

I have been on the road with all my camping gear for the last week and took the opportunity to experiment a bit. Tire pressure, 36 or 42....no difference. Rear suspension adjustments, also no difference but the rear end is slightly unstable if the dampening isn't set high enough. Normal....!The so called "Steering Damper" is fine and I have absolutely no reason to suspect the ball joint, wheel bearings or anything else, any of those would give other signs if they were at fault.

After all that I was at a loss figuring this out.....but I did....! My bike only wanders when the windscreen is in the high position....I push it down and it stops completely! My best guess on that one is that BMW's accountants only allowed wind tunnel testing time for the windscreen on the low position......! And to think they were so proud of that wind tunnel testing back in 85 when I bought a K100RS, they were even using that fact in their publicity.....! Times change...!

The solution however I do not have.....replacing that crappy front shock may help, or buying my first full face helmet in 25 years and keeping the screen down also could help. Mind you right now I am on the Oregon Coast and would rather keep it up because of the rain.....! :teeth
 

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Interesting point about the windshield.

I have both the tall (Comfort) shield and the standard RS one. I also have the fairing extensions at the hand grips. When I first put the fairing extensions on I had the comfort shield on. I usually used it in the low position. I was amazed at how suddenly side winds and buffeting were having in put into the bike. As time has gone by I now use the standard shield on low all the time and in weather above 55 take off the extra hand protection. Things seem really solid. I will watch for this when I put the extensions back on this winter. As for the tall shield, my wife as pillion, has a preference for the tall shield in the tall position. So I can't remember how things are riding single with it upright. I will watch for this next time I swap the windshield and have the extensions on for a ride with her.

NCS
 

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My 03 GT wanders a little also. It's just a little nervious. Sitting as far forward as you can reduces the twichyness. Raising the windsheild makes it worse. Above 90 it's fine and planted. I just think it needs more weight on the front to calm down.
Mine came with a spacer installed in the rear wheel. When removed it's more twichy upfront but the Pull To The Right issue is greatly reduced. With the spacer in it's more planted but plows/pulls to the right more requiring me to countersteer to compensate. I choose to live with the faster steering and twichyness. Counter steering all the time wears me out. It's a common problem with these bikes. Live with it.
 

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NCStephen said:
Interesting point about the windshield.

I have both the tall (Comfort) shield and the standard RS one. I also have the fairing extensions at the hand grips. When I first put the fairing extensions on I had the comfort shield on. I usually used it in the low position. I was amazed at how suddenly side winds and buffeting were having in put into the bike. As time has gone by I now use the standard shield on low all the time and in weather above 55 take off the extra hand protection. Things seem really solid. I will watch for this when I put the extensions back on this winter. As for the tall shield, my wife as pillion, has a preference for the tall shield in the tall position. So I can't remember how things are riding single with it upright. I will watch for this next time I swap the windshield and have the extensions on for a ride with her.

NCS
I just came back from a one week, 2500 miles ride through Idaho,Montana,Oregon,California,Washington and back to BC.....and like I said in a previous post took the opportunity to look into that wandering issue on my bike. My bike came with the fairing extensions on the upper part, and I have been wondering if they could also be part of the problem combined with the windscreen in the high position.....Maybe the air finds its way between the screen and the extensions destabilizing the bike, just a theory but I will try sticking some flag tape on the screen and do my own "wind tunnel testing" on the road. Will also try riding without the extensions and see what happens.
I do know for sure that the original front shock does not have enough preload, at least to my liking,so possibly does not push the front down enough into the road and could certainly be part of the problem.
However that wandering is also worse if you are in to high of a gear, the bike is just freewheeling and not pushing you through, so for my quick, easy and so much fun fix.......downshift and crank her up.....!!! :)
 

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Get a very slow-steering tire like a semi-round sport (almost flat) Maxxis (no longer made though). You'll need your pillion to help you steer it. Then you'll wish it would wander a bit. You'll think your steering head bearings are welded up.

It's all in the tire's cross-section, center-grove cut or lack of, and inflation as to how they wander. I think there's around 4 different types of cross sections out there now between all the brands. Soft compound pointies are great for the twisties, but wear out really fast on the highway (<2500 miles).

You can see the cross-section and triangular portions better looking at them on a tire rack with all the brands lined up and see what tire suits you're riding areas. Personally, I cannot stand the center-groove cut ones as they follow some road groove cuts and grates in bridges like a train. The zig-zag cut across the center-line vibrate the bars too much. The ones with all the little pads end up doing the heel-to-wear, scallop, feathering or whatever pattern and get noisy after a while of rocket starts and stops.

You can also take your fingernail and dig into the center and side tread to see if they have a dual-compound and how much difference you'll see between brands by your nail's impression mark.

It's a tire zoo out there I tell ya. :dunno:


Mack
 
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