I started feeling this when I got my tires changed.  At high speeds (65mph+), my handlebar will randomly give a very sharp (but small) tug to one direction (usually counterclockwise).  Its frequency is random but is more common at ~75-80mph as I decelerate by letting go of the throttle. 
At first, I thought my tires were not properly balanced but I've read that unbalanced tires would cause a vibration and not this issue. 
Next I'm thinking it's my bearings, but when I check for play/wobble at the wheel, it is completely sturdy.  I have 23k miles and haven't switched out the bearings.  Could this be the issue?
My last thought is that I just didn't put the wheels back on correctly.  I'm pretty sure everything is on there right, but checking again wouldn't hurt.

Has anyone else had similar issues?

(BTW this "tug" isn't something negligible.  I am honestly afraid every time it happens.  The handlebar enters into a small oscillation and almost feels like it's about to enter a speed-wobble and make me completely lose control.  Not fun.)

Hmmm.... I've got some bad news man.... it can honestly be any number of things. There's a laundry list of things to check : steering stem bearings, fork oil levels, forks seals, fork spring weight (still have the original springs?), rear shock condition, swingarm bushings, tire pressure, and probably a few others I'm forgetting ATM.

I can't honestly think it would be because of tire balancing and / wheel bearings though.

Well, Since its a problem since tirechange, and all we can do online is think logically i would say, only the parts that were touched could cause the problem. However, a problem i haven't tackled yet sounds like the problem you are having, and what i can tell you is that my front springs are leaky as F#$k. I did buy my tires with wheels attached and balancing weights installed. my bearings are Ok.

Soo, maybe go check on your oil levels?

But logically i would still say its your tires or something, since those were the only thing taken off when you had em changed (right?) And in my experience, a problem after a job, has to do with the things done in the job, not something else.

Your forks might be out of alignment.

Just thinking out loud. ... possibly as has been mentioned,  fork oil height, but one side much worse/lower? , so on decel as the forks compress then one side sags a little more?

... or. .  And just because of how you worded the problem...

Unconscious counter steering?.   When you 'let go' of the throttle at higher speeds (and higher than before maybe because you have fresh new confidence inspiring rubber!) You grip the left side bar a little tighter and it gets a little push because decel means body weight forward also..  push on the left bar (without really turning it much) and you will move the bike left!

You said usually so possibly in the potential scenario when it jerks to the right you ease off throttle but loosen left hand, add pressure to right bar and head right!?

Or still a mechanical issue of another type! ??

I mention the counter steering thing because it is something I occasionally have caught myself doing. ... I counter steer on purpose a lot too but if my attention wanders a little or my arms/shoulders etc are getting tired from spirited riding then it happens.

Just a alternative possibility to consider

Oh and the oscillation thing, whether its a serious issue to repair or just something to look at later. .. if I barely grip the bars with both hands on certain bumpier roads near me... and really bad once when I let go to 'practice hands free coasting' :rolleyes:  .. I got the death wobbles too, a quick and firm re grip of bars and it was gone!

So the oscillation can/does happen!

I'll check out the fork oil height.  My right fork is significantly dirtier than the left one.  I had thought it was just from brake dust since the rotor is on the right side of the wheel. I'll check it out later tonight.

I underestimated the effort of checking the fork oil level so I haven't gotten around to it yet.  However, I did notice some liquid around the inner tube of the right damper. 

Here are a couple pictures:
http://i.imgur.com/8gbRmCt.jpg
http://i.imgur.com/pAuP6vm.jpg

In the second image, you can spot some grime accumulating near the top.  There is also dirt sticking to the right side of the front tire fender which leads me to believe this has been going on for awhile. The left damper seems very clean, comparatively. Hopefully this is the source of my wobbling issue.

There are some really nasty speed bumps which have recently (~8 months ago) been installed in my apartment complex (which are impossible to avoid, minus riding up the sidewalk).  I've hit them harder than I should've a couple times and have felt an impact in the damper.  I'm guessing this is the cause of my issue but who knows.

Any advice on fixing this?  I'll have to replace the seals at least... maybe more once I open it up.

I am not sure if the fork oil level would cause something like that... my forks have been leaking since last October with the left one so bad that when I ride the oil would literally build up and splash off the back of the dust seal onto the frame and my SHOE 

...but I never had any wobbles or sharp grabs when riding or turning. (Just an oily shoe and dirty frame grrrr)

I hope ya get your seals replaced and find the source of your troubles!! That tug you described in the first post certainly sounds terrifying.

If you're not familiar with changing fork seals you might find this helpful

https://youtu.be/vrmYJgcGX30

Quote from: baronduff on May 22, 2015, 11:11:54 AM
If you're not familiar with changing fork seals you might find this helpful

https://youtu.be/vrmYJgcGX30

Love Delboy, his stuff is great!

So I finally found time to change my fork seals!   
The front wheel doesn't seem to have sudden jerking movements anymore.  It still doesn't seem very stable (this could just be paranoia) so I'm not convinced this really solved my issue.
Regardless, I've already noticed a considerable amount of oil leakage from BOTH forks. http://i.imgur.com/34gNugg.jpg

I used these fork seals: http://i.imgur.com/Os53rum.jpg
Item# 22-55148
OEM# 55-148
From what I've found, these should be the correct ones. (please let me know if I'm wrong)
I also used Maxima 56901 15WT Standard Hydraulic Fork Oil found here: http://www.amazon.com/Maxima-56901-15WT-Standard-Hydraulic/dp/B000WKAV2U/ref=sr_1_1?ie=UTF8&qid=1437886765&sr=8-1&keywords=Maxima+56901+15WT+Standard+Hydraulic

I added the full liter of oil (so half-liter on each side) not knowing the exact amount.  My thinking was 'more oil = slightly higher stiffness.'  Is this a big no-no?
I'm debating taking the forks off again and reducing the amount of oil.  What is the proper fork oil height? (I'm measuring the air gap from the top of the fork when the spring, washer, and spacer are removed)

Any other ideas on why my forks are leaking?

You have way too much oil, should be less than 400 millilitres, but you must use the depth measurement,  not go by volume is some oil also remains when you drain.
What did your oil look like when you drained , if it was a black mess, it's a chance that your bushes are worn and are sticking, when's the teflon could gets worn through the  Bush itself starts to wear very quickly. This can cause catching and uneven movement of your forks

Sent from my SGH-I337M using Tapatalk

Quote from: cpaiin on July 25, 2015, 10:11:33 PM
So I finally found time to change my fork seals!   
The front wheel doesn't seem to have sudden jerking movements anymore.  It still doesn't seem very stable (this could just be paranoia) so I'm not convinced this really solved my issue.
Regardless, I've already noticed a considerable amount of oil leakage from BOTH forks. http://i.imgur.com/34gNugg.jpg

I used these fork seals: http://i.imgur.com/Os53rum.jpg
Item# 22-55148
OEM# 55-148
From what I've found, these should be the correct ones. (please let me know if I'm wrong)
I also used Maxima 56901 15WT Standard Hydraulic Fork Oil found here: http://www.amazon.com/Maxima-56901-15WT-Standard-Hydraulic/dp/B000WKAV2U/ref=sr_1_1?ie=UTF8&qid=1437886765&sr=8-1&keywords=Maxima+56901+15WT+Standard+Hydraulic

I added the full liter of oil (so half-liter on each side) not knowing the exact amount.  My thinking was 'more oil = slightly higher stiffness.'  Is this a big no-no?
I'm debating taking the forks off again and reducing the amount of oil.  What is the proper fork oil height? (I'm measuring the air gap from the top of the fork when the spring, washer, and spacer are removed)

Any other ideas on why my forks are leaking?

after dealing with other suzuki bikes, do not buy aftermarket fork seals. The OEM ones always work best and last the longest.

+1 on the OEM seals...

  the pyramid parts ones are terrible!... they have been known to work ( I've had both and the pyramid ones don't even look right compared to OEM ) but I remember seeing quite a number of complaints/issues with them on this forum!

Damn.
Well I'll order the OEM seals and hope that works.

Anyone know the proper fork oil height?