GL1200A won’t keep a straight line


Information and questions on GL1200 Goldwings (1984-1987)
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We3jones
Posts: 6
Joined: Sun Sep 18, 2022 6:13 am
Location: Carlisle, PA
Motorcycle: 1987 GL1200A Aspencade

GL1200A won’t keep a straight line

Post by We3jones »



My father purchased an 87 GL 1200a new back in 87. Now has 73,000 miles between my dad and I. He’s now older and upgraded to three wheels. So I am riding the GL full time now. Been riding it every day this past year and notice it’s very hard to keep a straight line going down the interstate. It wants to weave back and forth in the lanes. I have tired a hundred different things. Any ideas would be greatly appreciated. Thank you.


joecoolsuncle
Posts: 562
Joined: Sun Sep 26, 2021 6:10 am
Location: oxford, ar
Motorcycle: 1984 gl1200a

Re: GL1200A won’t keep a straight line

Post by joecoolsuncle »

good luck with that. some cover that fact up with "it handles great and it feels much lighter over 35mph".
We3jones
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Joined: Sun Sep 18, 2022 6:13 am
Location: Carlisle, PA
Motorcycle: 1987 GL1200A Aspencade

Re: GL1200A won’t keep a straight line

Post by We3jones »

Thanks. I seem to find that response a lot searching for answers. I have checked and adjusted the front forks and axle. Changed tires. Replaced the steering neck bearings. Checked and adjusted center alignment from front to rear wheels. Running the bike through water on the shop floor. Front and rear wheels track perfectly. This isn’t to much issue of I’m riding alone. But when with a group. I have to stay at the back of the group. I worry being beside people.
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julimike54
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Location: Euless, Texas
Motorcycle: 1986 GL1200A original owner
2016 HD FLTRU

Re: GL1200A won’t keep a straight line

Post by julimike54 »

Did you follow the Factory Service manual for Steering Stem Adjustment?
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Riding anything is a good day!
Mike
We3jones
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Joined: Sun Sep 18, 2022 6:13 am
Location: Carlisle, PA
Motorcycle: 1987 GL1200A Aspencade

Re: GL1200A won’t keep a straight line

Post by We3jones »

Yes I did. Had some trouble finding the right bearings being almost all the parts for this bike are discontinued. I had to pull the bearing and cross the part number with Timken locally here. But everything is back together and torqued to factory specs. One thing I am finding mixed information for. There is small numbered dials on the bottom of both forks. Labeled 1-4. The manual is not real clear. What does this adjustment do? And what is the proper adjustment? Thanks for the help everyone.
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julimike54
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Location: Euless, Texas
Motorcycle: 1986 GL1200A original owner
2016 HD FLTRU

Re: GL1200A won’t keep a straight line

Post by julimike54 »

I didn't see where you mentioned the pulled weight on each bar.....
The TRAC is an anti dive system that makes small adjustments to the forks, it is set by trial and error of what feels best to you, mine are set on 3 for both forks. Going from memory, I believe there are supposed to be set the same, but just memory.
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Riding anything is a good day!
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Rambozo
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Motorcycle: 1992 GL1500 Aspencade
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Re: GL1200A won’t keep a straight line

Post by Rambozo »

Did you check the swingarm bushings?
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Bike...and Dennis
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Location: Glendale, Arizona
Motorcycle: 1987 GL1200I

Re: GL1200A won’t keep a straight line

Post by Bike...and Dennis »

Did you change the rear tire, too? And what air pressure are you running front and rear?
The weaving is generally associated with the steering head bearings being too tight, but, if the weave started before you changed them...
We3jones
Posts: 6
Joined: Sun Sep 18, 2022 6:13 am
Location: Carlisle, PA
Motorcycle: 1987 GL1200A Aspencade

Re: GL1200A won’t keep a straight line

Post by We3jones »

Thanks. It did start before the bearing was changed. No difference after. My dad just put new tires on it right before he decided to retire from two wheels. But he put those cheap ass Shinko tires on it. I have tried several different tire pressures. It seems to be the best at around 25 psi. We just got back from a 566 mile trip on Skyline drive in VA. I was two up this time. Changing pressure the entire ride. This trip is what made me join the form and try to find some answers. Until this is figured out. I will never take this bike two up on a trip like this again.
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Rambozo
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Re: GL1200A won’t keep a straight line

Post by Rambozo »

That's kinda low. The owners manual for that bike lists 32psi for the front and 32 to 40 for the rear depending on load.
We3jones
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Joined: Sun Sep 18, 2022 6:13 am
Location: Carlisle, PA
Motorcycle: 1987 GL1200A Aspencade

Re: GL1200A won’t keep a straight line

Post by We3jones »

Thank you. I will give the higher pressures another try. Seems the weaving was worse when I ran the recommended pressure. Do you think this whole issue could be the cheap tires? I also have a 2005 GSXR 750 and a 2001 BMW 1150rs. I tried the Shinko tires on my GSXR and they didn’t stick to the roads very well at all. Since then I have been running Michelin 2CTs on the GSXR and Michelin radials on the 1150rs and those tires have been awesome. I would really like to figure this out. The GL1200 is a much nice ride with two people on long trips. Thanks for the help everyone. Really appreciate your time.
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Bike...and Dennis
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Location: Glendale, Arizona
Motorcycle: 1987 GL1200I

Re: GL1200A won’t keep a straight line

Post by Bike...and Dennis »

25 is way, WAY too low.
I run more like 38 & 40 and the bike tracks fairly straight. Slight drift to the right is normal due to the incline of our roads.

I'm running Pirelli M66 Route tires and they work pretty well for budget tires. Way better than Dunlops and way, WAY better than Metzler. They don't last long (15K) but at least they don't take on the slow speed death wobble when the rear starts to wear.
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Rambozo
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Re: GL1200A won’t keep a straight line

Post by Rambozo »

Have you been using high ethanol fuel? Can the bike touch the handlebar tip to the headlight?
We3jones
Posts: 6
Joined: Sun Sep 18, 2022 6:13 am
Location: Carlisle, PA
Motorcycle: 1987 GL1200A Aspencade

Re: GL1200A won’t keep a straight line

Post by We3jones »

So I bumped tire pressure up to 36 and rode it to a clients job yesterday. Did about 70 miles with it and it’s a little better at 36psi. I think I’m going to run it at this for a while and see how it feels. Thanks for the help.
Wreckster
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Location: Hudson valley, NY
Motorcycle: 1986 1200A, 2014 V-Strom

Re: GL1200A won’t keep a straight line

Post by Wreckster »

Was going to say, maybe they're not crazy stable but I sure as heck haven't had trouble keeping lane position. 36 front is what I run. Something else to consider, I've also rebuilt the rear shocks and forks. The fork springs definitely soften with age, far too much really. In turn, the front end might be sitting lower than it should be and that can certainly cause for a little more twitchy a ride. I went progressives, maybe could have gone up just a tad with oil thickness but I'm happy with it. The rear, springs are soft there too but I have the air pressure a bit higher to compensate and level off the bike. If it's really that twitchy, I'd likely believe that something isn't right, swing arm bushings for example. Get the rear off the ground and put some muscle into moving the read wheel side to side, from bottom and rear. It shouldn't budge one bit. Tires, that's also possible. Wrong tires can do some strange stuff.
joecoolsuncle
Posts: 562
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Location: oxford, ar
Motorcycle: 1984 gl1200a

Re: GL1200A won’t keep a straight line

Post by joecoolsuncle »

Bike...and Dennis wrote: Mon Sep 19, 2022 9:58 pm 25 is way, WAY too low.
I run more like 38 & 40 and the bike tracks fairly straight. Slight drift to the right is normal due to the incline of our roads.

I'm running Pirelli M66 Route tires and they work pretty well for budget tires. Way better than Dunlops and way, WAY better than Metzler. They don't last long (15K) but at least they don't take on the slow speed death wobble when the rear starts to wear.
what size pirelli m66 are you running ? i would love to get 15k miles from a "budget tire" ! thanks
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Ohara
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Location: Ontario Canada
Motorcycle: 1986 Interstate
1986 Aspencade

Re: GL1200A won’t keep a straight line

Post by Ohara »

Have found Shinko tire on the front works very good, on the rear they can contribute to weaving or following cracks in the road. Try a higher quality tire on the rear using 40 psi.
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Bike...and Dennis
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Location: Glendale, Arizona
Motorcycle: 1987 GL1200I

Re: GL1200A won’t keep a straight line

Post by Bike...and Dennis »

Tire sizes are stock. 130/90 in front and 150/90 in back.

Something just came to mind. You're not running radials, are you?


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