CB1100 "yaw" (former sailor here...)

[kvdv_imp]

On our recent trip down the coast, I happened to look down at my handlebars while underway and noticed that they and the rest of the front end assembly were ever so slightly aiming to the right (maybe 2 degrees tops, but noticeable) even as I was moving in a perfectly straight line. I continued to check on every straightaway, and it definitely was out of alignment. Having recently had new tires put on, I had a look at the rear axle adjusters at the next stop to see if they were not adjusted equally on each side. Sure enough, if the indicator notches are anything to go by, it looked to me like the left (port) side of the rear axle was just ever so slightly forward of the right (starboard) side. Doing the geometry in my head, I imagined that having the rear wheel out of adjustment to the right would force the handlebars to settle at a similar angle to keep going in a straight line, resulting in the bike crabbing or yawing down the road ever so slightly.
Am I on the right track here? It seems a simple matter to loosen the rear axle, re-adjust to true, and snug it back down, and if I get it right the yaw should disappear, yes? Is there anything else I should be thinking of? I'll have a look at the chain and sprockets while I'm at it, hopefully no damage has been done...
Thanks as always for your kind guidance! - K

 

[Toddman_imp]

The important thing is chain and sprocket alignment. The counter sprocket and rear wheel sprocket have to line up. Look up string aligning your motorcycle and you'll get the picture. You can't always trust the marks on the swingarm.

 

[kvdv_imp]

The important thing is chain and sprocket alignment. The counter sprocket and rear wheel sprocket have to line up. Look up string aligning your motorcycle and you'll get the picture. You can't always trust the marks on the swingarm.

Understood, and thanks... but to my original question, would rear wheel misalignment cause the steering behavior I described? I had never seen anything like that previously on this or any other bike I've owned, and I'd like to check my theory with folks who know more than I do... - K

 

[postoak_imp]

Are the bars canted when you are at a stop? If this bike is like my Nighthawk 750, there's rubber between the bar and the clamps and the bars can get off after awhile. The solution is simply to loosen the clamps and let the bars return to the correct position.

 

[kvdv_imp]

Are the bars canted when you are at a stop? If this bike is like my Nighthawk 750, there's rubber between the bar and the clamps and the bars can get off after awhile. The solution is simply to loosen the clamps and let the bars return to the correct position.

good question...no, at a stop I can easily align the bars and forks so that they're perfectly parallel to the front of the tank. As soon as I start to roll in a straight line again, I can look down and see that the entire front end (triple tree, forks, handlebars) is pointing ever so slightly to the right. I'm going to do an oil change this week and while I'm at it I'm going to look the rear wheel alignment...I still think that might be the cause. I'll report back with results. Thanks! - K

 

[Frulk_imp]

Funny. Mine is the same way. I just never pursued doing anything about it up to this point.

 

[johnf514_imp]

Noticed mine is this way too, straight at a stop, canted slightly right while in a straight line. No idea why, but I did just get a new rear this morning, and am now wondering if it is slightly out of alignment too.

 

[Toddman_imp]

Well I don't know about misalignment but when i turn to the left, i can hear/feel one of my front brake disks rubbing (l guess on the pad in the caliper).

 

[the Ferret]

Got to admit I have never even looked at mine and don't think I want to. Ride more...worry less!

Well I don't know about misalignment but when i turn to the left, i can hear/feel one of my front brake disks rubbing (l guess on the pad in the caliper).

Whaaaat ? I would think that would be impossible unless your axle nut is loose.

 

[kennyw]

Yes, a rear wheel being misaligned could be a cause of the condition you describe. However, I would not worry about it unless your sprockets are misaligned as well.

 

[kvdv_imp]

Hey everyone -
I finally had a chance to play around with the rear wheel adjustment while also doing an oil change this past Friday night after work. I was hoping not only to correct that funky front end orientation but also take care of some excessive chain slack at the same time.

The verdict: mission accomplished on both! By simply bringing the left end of the rear axle ever so slightly aft, and bringing the right end of the rear axle slightly forward and snugging everything back down, the front end now is true again when rolling in a straight line. For an OCD guy like me, that makes me very happy. And having the chain slack back within spec makes shifting and low-speed throttle transitions buttery smooth again. I was a bit surprised at the results after making very tiny adjustments...maybe a half a turn or less per each axle adjuster.

Anyway, we're back in business. Thanks as always for your pointers and input. What a great forum this is.
- K

 

[LongRanger_imp]

I've had the same experience. The proper chain tension seems to make a noticeable difference in shifting smoothness.

 

[Cormanus]

I've had the same experience. The proper chain tension seems to make a noticeable difference in shifting smoothness.

+1

 

[uscgmac_imp]

All roads in the U.S. have a slight grading to allow for water run off. This could add to the illusion that your alignment is off but it's actually your bike correcting for the natural road grade

Sent from my SM-T350 using Tapatalk

 

[kvdv_imp]

All roads in the U.S. have a slight grading to allow for water run off. This could add to the illusion that your alignment is off but it's actually your bike correcting for the natural road grade

Sent from my SM-T350 using Tapatalk

That thought had crossed my mind, but then I ruled it out. Considering that adjusting the rear axle alignment corrected the problem, I've got to stick with my first theory. I even double checked with a local mechanic I trust, and he agreed. He said it probably happens quite a bit but not everyone else is OCD enough to notice like I am.