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Discussion Starter #1
Hi,

I think I know what I did wrong, but as always I would like your input and to see if anyone else has experienced this issue before I start throwing money at it.

My bike handled perfect until I had the front and rear tires changed AND rebuilt my steering damper. Now I notice it takes constant slight corrections to keep the bike going straight. I tend to weave back and forth a bit and it's annoying. The bike still handles okay but it's different than it was before I made these changes.

Since I did this all at once, it is either the tires or the damper. I followed the Youtube video of taking the damper apart, cleaning it and used either 5w or 7.5w oil when reassembling it. I have to check what oil I used but maybe it was too light?? Would that cause this?

For the tires, I had a new Bridgestone BT-020M installed on the front and a Metzeler ME880 put on the rear. Both are rated for the K1200LT and it seems to be a common combo from what I have read on here. I've also tried various air pressures with no effect on this weaving issue.

SO, is the steering damper causing this and should I replace it?

Chris
 

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You should of but the bridge on the back and mez on the front but I do not think that has any thing to do with it
 

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Discussion Starter #3
Gary,

Thanks for pointing that out. My bad. I just went and checked and realized I put Bridgestone tires on both ends and they are both bias ply (thought maybe a radial got put on and was causing this).

Chris
 

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I'm going to say to look at the front tire as being suspect.

Of course, new tires feel different than the wore out pair you had been riding for thousands of miles and will feel like the bike turns in better with less effort.

The steering dampener is for violent head shake and would not dampen weaving.
 

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I've had to run bias rear with a radial front on the LT. Rear showing cords on a trip. Was in the middle of nowhere.So I had to replace with a bias Dunlop to get me home. It handled just fine.
 

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If this problem is occurring at slower speeds it is possible that you have some binding in the steering. On a normal bike with standard head stock and tapered roller bearings, the problem occurs when the bearings become notchy.
Is there some physical binding in the steering since reconnecting the steering damper (other than the normal damping resistance of course).
 

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I would bet the dampener is giving you slight resistance which will cause the weaving. I over tightened the steering head bearings on an old triumph years ago and that caused the bike to weave until I loosened them. Put it up on center stand front tire off the ground and slowly turn it back and for and if you feel any resistance from the steering dampener that is your problem. After moving back and forth slowly increase the motion and determine when the damper kicks in. it shouldn't kick in until back and forth motion becomes pretty quick.

Good luck
 

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I would bet the dampener is giving you slight resistance which will cause the weaving. I over tightened the steering head bearings on an old triumph years ago and that caused the bike to weave until I loosened them. Put it up on center stand front tire off the ground and slowly turn it back and for and if you feel any resistance from the steering dampener that is your problem. After moving back and forth slowly increase the motion and determine when the damper kicks in. it shouldn't kick in until back and forth motion becomes pretty quick.

Good luck
I was going to say that it couldn't be the damper, however.....I'm having second thoughts.

When I serviced the steering damper on my LT, I used 7 wt fork oil at first, and the steering felt sluggish. (scissor jack under the engine to lift the front wheel) changed it to 5 wt and it felt much better.

You should only feel the presence of the damper with Very quick steering movement.

Try disconnecting it from the control arm, go for a ride & see if the issue goes away.
 

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From memory on the LT wasn't there a step where you installed the axle and then bounced the front end a few times to make sure the axle / wheel assembly was properly aligned. If the front tire is slightly out of alignment wouldn't this also cause this issue?
 
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Rand,

Good idea to disconnect damper and test ride, easy to do and I bet problem solved.


I was going to say that it couldn't be the damper, however.....I'm having second thoughts.

When I serviced the steering damper on my LT, I used 7 wt fork oil at first, and the steering felt sluggish. (scissor jack under the engine to lift the front wheel) changed it to 5 wt and it felt much better.

You should only feel the presence of the damper with Very quick steering movement.

Try disconnecting it from the control arm, go for a ride & see if the issue goes away.
 

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I would start with what Dean said. adjust/correct tire pressure. KISS first.
if it was 70 or so in the shop and 45 or so outside you already have lost air pressure.

Good luck
 

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Discussion Starter #13
Thanks for all the input, things I hadn't thought of. This weekend I will:

Double check tire air pressure. I run 48 psi rear and 42 psi front. It seemed to handle fine with those pressures in the past and that is what I set them to after I got the tires back from the shop (btw, I did remove the wheels and reinstalled them myself).

Research the front wheel install procedure. If there is some type of bouncing to seat/align the axle before torqueing things down, I didn't do it so maybe that's an issue. Then a test ride.

If the issue remains, I will check for any type of binding in the front end with/without the damper and then try a test ride without the damper.

Thanks for the help,
Chris
 

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I just had new tires put on my bike as well. At the shop his gauge said 42 front and 48 rear, I installed the tires and ended up with the same issue as you. At very low speeds the bike seemed to weave, or feel drunk. It did fine at higher speeds, but at anything less than 7 MPH, this would happen.
I checked the tire pressure, and sure enough, it was low. Both tires were at least 10lbs low. I think his gauge, mounted on his mounting machine was off. I doubt I could have lost 10 PSI in 3 day from both brand new tires.
Check your pressure, I would bet this is it. And its free, so it should be your first check.
 

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Research the front wheel install procedure. If there is some type of bouncing to seat/align the axle before torqueing things down, I didn't do it so maybe that's an issue. Then a test ride.
Here's the page from the online version of the BMW manual, they only address that point as a "Note" ie,
Note:
Begin by tightening the quick-release axle (1). Press
down on the forks and release them; repeat this action
several times and then tighten the pinch
bolts (2, 5).

Page is attached.

Clymer manual describes it in a little more detail...
 

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Discussion Starter #16
Thank you all for the advice and boy do I feel silly. The weaving was due to low tire pressure both front and rear. I checked them today with my tire gauge and they looked fine. I then used the gauge on my tire pump (MiniPro Motopump) and the tires were 10 psi lower!

I filled them to the correct pressure using the Motopump's gauge which seems accurate. Took a test ride and things are just fine. I threw away the Slime brand gauge that was off. I am now in the market for a GOOD air gauge, anyone have any suggestions since all the local parts stores sell are cheap ones.

Once again, thanks for the suggestions and I am very happy this repair was free...... Also, it appears that my rebuilding of the steering damper was fine as it is working as it should.

Thank you,
Chris
 

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I figured it would be, as I said, I had the same issue and it bugged me because I thought the pressure was correct. Reset the pressure, and they are fine now. I too am looking for a quality gauge. Let me know what you find, and I will do the same for you.
 

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All in all the digital (cheap or expensive) have shown to have the best accuracy. There was an extensive review in one of the bike magazines a few years back and that was the general consensus.
 
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