bike tracks left

[79-GS550-L]

Hi everyone,

My bike wants to lean left. To get it to go straight I have to lean a little to the right or put a bit of pressure on the right handlebar. When I pull in the clutch and brake gently it wobbles from side to side, I'm assuming the two are related. I just changed the oil in the front forks, but it didn't help. Could this be an alignment issue? How do I check/adjust that?

On a different note, my fork seals are not in the best of condition. How hard is it to change them?

[Dave8338]

Sounds as if your forks are tweeked. Put the bike on the center stand and measure from the axle up to a known point on the engine ie. head bolt / whatever. Then go around and measure the other side. When you get both sides to measure exactly the same (turning the bars left or right), step back and have a look. I'll bet the left fork will be behind the right in the track. If you have a laser level / projector you can lay it on the floor next to the front wheel and measure the distance side to side on the rear wheel.

[chef1366]

What shape is the tire in? Does the rim turn easily when spun with it in the air? Is there a caliper piston sticking on one side? And then are your forks tweaked.

[79-GS550-L]

Sounds as if your forks are tweeked. Put the bike on the center stand and measure from the axle up to a known point on the engine ie. head bolt / whatever. Then go around and measure the other side. When you get both sides to measure exactly the same (turning the bars left or right), step back and have a look. I'll bet the left fork will be behind the right in the track. If you have a laser level / projector you can lay it on the floor next to the front wheel and measure the distance side to side on the rear wheel.

Ok, that is REALLY hard to measure! I'm just using a tape measure, my garage floor is not quite level but almost, and when I put my bike on the center stand the little handle thing is pressed into the ground. So I don't know how accurate this is, but I lined up the front wheel so that the center of the axle was the same distance to the first horizontal fin on the head on both sides. Then I butted up the tape measure to where the fork seals are and measured that to the same point on the head on either side. The left one was about 1/8th inch shorter, so if my measurements are to be trusted the left fork is behind the right one.

So what does that mean? Can forks be straightened? Or do I need to replace them completely?

[79-GS550-L]

What shape is the tire in? Does the rim turn easily when spun with it in the air? Is there a caliper piston sticking on one side? And then are your forks tweaked.

Tire is in great shape, looks pretty new. It's hard to tell how easily the front tire spins, I'm not sure how to put it in the air. If I put the bike on the center stand the rear wheel is off the ground. I'll try to get my wife to sit on the very back seat to lift off the front wheel. I don't know if she'll do it though :-D But I don't think the caliper is sticking. Plus, I only have one rotor/caliper (on the right side), not on both sides (do some GS's have two?)

[79-GS550-L]

Ok, front tire spins freely, and there is no side-to-side play between the top and bottom (so I guess the bearings are good).

[79-GS550-L]

Whoops, my front caliper is on the left side, not the right

Bump? Any more suggestions?

[Road_Clam]

Whoops, my front caliper is on the left side, not the right

Bump? Any more suggestions?

The issue might not in the front, but the rear. Check the rear wheel bearings, and the swingarm bearings.

[79-GS550-L]

The issue might not in the front, but the rear. Check the rear wheel bearings, and the swingarm bearings.

Let's see... the rear wheel does not have any side-to-side play between the top & bottom. The wheel does not spin as freely as the front (in neutral), but I guess it wouldn't since it's got the chain and all that to pull. How do I check the swingarm bearings? And could it be that the wheel is not pointed straight, due to the chain adjusters? How can I measure how straight the wheel is?

[80GS1000]

Check the markers on both sides of the swingarm to make sure the rear axle is in the same position of both sides of the swinger - ie it's straight. I find it helpful to use a set of calipers to measure from the rear of the axle to the rear of the swingarm adjustment area to make sure both sides are within ~1 mm of each other.

[79-GS550-L]

both adjusters are lined up on the same line. Can I adjust the rear wheel to compensate for the pulling left? I guess I'd make the rear wheel point a little more left. Or is that just a really bad idea? How do I adjust them, just turn the horizontal bolt at the back of the adjuster? Or do I need to loosen something first?

[79-GS550-L]

Bump again... I'm still scratching my head on this. To recap: the bike tends to drift to the left at steady speed, and it wobbles when coasting slowly (~10 mph). I tried stretching out bits of string to check the alignment of the wheels, but since the back wheel is wider than the front, it doesn't really help. I sighted along the top of the chain and it is in a straight line with the sprockets. There is no sideways play anywhere. I can't tell if the forks are bent or out of alignment, it's too hard to measure accurately.

I heard the forks can be aligned by loosening the fork pinch clamps and bouncing the front end then re-rightening. But I can't figure out how this works. Wouldn't that just cause the front-end to sag onto the forks? And how does that "align" them anyways?

It's only a problem around 10 mph or so, but I feel like I'm about to dump the bike every time I have to stop at a light. Anyone have any other ideas? Do I need to take it to a shop (shudder)?

[Steve]

Check the markers on both sides of the swingarm to make sure the rear axle is in the same position of both sides of the swinger - ie it's straight.

Actually, the markers are notoriously inaccurate. Better to use a couple of straightedges or string like you did. Yes, the rear tire is wider, but you can still get a good idea, especially if you clamp some spacers to the back edge of the front tire to make it the same width or just a bit wider than the rear tire.
Since the bike it tracking left, you need to move the right side of the rear axle forward just a bit.

I heard the forks can be aligned by loosening the fork pinch clamps and bouncing the front end then re-rightening. But I can't figure out how this works. Wouldn't that just cause the front-end to sag onto the forks? And how does that "align" them anyways?

There are upper pinch clamps and lower pinch clamps. Depending on the bike, there are also pinch clamps where the axle mounts to the forks. Loosen the lower triple tree clamps and the axle clamps. Bounce the forks a couple of times, then tighten everything back up. How this "aligns" everything is simple. If the axle is tightened incorrectly, it will put a binding twist on the fork tubes. The fork tubes will twist in their clams and make the bike go crooked down the road. By loosening all but the top triple tree clamps, you can compress the forks and let them find their 'home' position freely. After they have settled into place, tighten the lower triple tree, then the axle.

It's only a problem around 10 mph or so, but I feel like I'm about to dump the bike every time I have to stop at a light. Anyone have any other ideas? Do I need to take it to a shop (shudder)?

The obvious solution is don't stop at lights. :shock:
Another possibility for the wobble (but not the left-tracking) is steering head bearings. Put the bike on the centerstand and lift the front wheel off the ground. Turn the handlebars from side to side, paying particular attention when they go past straight-ahead. Is there a notch in the steering, or is it smooth all the way? The notch is common in higher-mileage bikes due to constant pounding of the bearings into the races. Replacing the steering head bearings is the only solution there.

If the steering is smooth, there is a chance that the bearings have loosened up a bit and just need to be re-torqued. Sometimes it takes a special tool to get the right torque value, but you might be able to just snug them up a touch with the tools you already have.


.

[79-GS550-L]

Ahah! There IS a notch in the middle of the steering. And if I swing it back and forth slightly through that notch, that's exactly what my wobble feels like! Ok, new steering head bearings for me! Thanks so much!

I'm a bit confused as to what I should order. I'm looking at bikebandit's steering stem schematic, and I'm guessing I need 25, 29, 27, 2x26, 3, and 2x28? There is nothing in the parts list that says "bearing" or "race". Are there really only 2 ball bearings ("steel ball") in the thing? Or are there a bunch and they're just not showing them?

While I'm at it, I'm going to replace my fork seals. Is there anything else I need to order, like other seals that will need to be replaced or things that I might as well replace at the same time?

[Dave8338]

There are more than two, more like 12-15 separate balls per bearing and 2-lower and 2-upper races. If you're going to do the fork seals, you may want to look into the progressive rate springs...everyone here raves about them, though I don't have them in mine, YET! :-D