Diagnosing handling problems. Solution

I am at a loss to describe the handling problems. I dont think there is anything in the front end that hasn't been replaced- springs, seals, bearings
New rear tire, on the center stand it spins freely and looks perfect.
I've tried more air, less air.
I feel like an idiot trying to explain how it feels..... Its sort of like one over correction after another?
so, I found a hill about 2 miles long, that has a nice long even grade with a fairly new surface.
Got going about 50, bumped it into neutral and let go the handle bars. put my hands on my thighs and rolled down
It kept wanting to drift the to the Left- I'd horse it center with my body center, or even a tad right and it would drift back to the left- not violently, but repeatedly.
Ok, armed with that, does that give an insight where I need to start looking?
I am open to suggestions. thanks in advance

I copied this from a post from Jeff Saunders (owner of Z1 enterprises)

Motorcycle Wobble Causes

There's a LONG list of potential area that can cause this.

These are not in any particular order

Wheel bearings

Steering bearings - repack grease, check tightness

Swing arm bushings/sleeves/bearings - replace if worn, repack grease

Fork springs aging - check spring length

Unequal fork oil - if seals leak, then your damping can be ineffective

Rear shocks aging, damper leaks - if you have oil leaking from the seals, the damping is toast.

Worn Tires/Mismatched tires/tire pressures/wrong size tires
Wheel alignment - don't trust the chain adjusters - I visually align the wheels.

Bent rims/broken spokes - get the wheels off the ground and spin them - check for runout / damage

Front disc warped - check for runout

Steering & swing arm bearings are very common problems, but so are tire issues (pressure/mismatch) and wheel alignment.

Are the tires and wheels balanced? Any of the brakes sticking? Are the tires aligned with each other? You indicate you have a new rear tire, what shape is the front one in?

MFolks wrote: I copied this from a post from Jeff Saunders (owner of Z1 enterprises)

Motorcycle Wobble Causes

There's a LONG list of potential area that can cause this.

These are not in any particular order

Wheel bearings new

Steering bearings - repack grease, check tightness done

Swing arm bushings/sleeves/bearings - replace if worn, repack greasehmmm

Fork springs aging - check spring length new

Unequal fork oil - if seals leak, then your damping can be ineffective done

Rear shocks aging, damper leaks - if you have oil leaking from the seals, the damping is toast. Hmmmmm........this could be it, it has those air shocks...I'm wondering..

Worn Tires/Mismatched tires/tire pressures/wrong size tires new/checked
Wheel alignment - don't trust the chain adjusters - I visually align the wheels.possible

Bent rims/broken spokes - get the wheels off the ground and spin them - check for runout / damage

Front disc warped - check for runout

Steering & swing arm bearings are very common problems, but so are tire issues (pressure/mismatch) and wheel alignment.

thanks, its a check list

gd4now wrote: Are the tires and wheels balanced? Any of the brakes sticking? Are the tires aligned with each other? You indicate you have a new rear tire, what shape is the front one in?

Both new tires- balanced.
NOT sure how to align the front to the rear, suppose old school way, jackstands, string?
Its for the 1100 shaftie in the sig

Its slight, ever so slight, but I have a hard on for NOT tolerating this sort of thing.

"Front disc warped - check for runout".... Bingo!

With my original build, would run with zero problems until 75mph +...
Bump down the speed and back to no issues...
Hmmm.... :S

Culprit:
* Raise the front end, and remove front fender.
* While standing directly over the brake rotor/rim, free spin front tire.
* Look for warp in rotor hitting brake pads, rim wobble etc...

New rotors $$$... :pinch: but well worth it...

Just my story...

Yup, oil change eminent when filter arrives, so jack stands and start looking at ^ suggestions.
Its not excessive, but..I am suspecting rear shock problems as tire wear is perfect, precise even.
Could be swingarm bushings too, painful but cheap easy fix

if u have old swing arm ushings, i would start there.
u dont need to check front to back tire as much as back tire to frame.
find a point in the exact same place, on booth sides of the bike, then measure from there back to the rear axle. 1 good place to use is the swingarm bolt. but be aware that the nut end and the bolt end r dif sizes, so u must compensate for this in your measurement.

Lots of good advice already given, have you checked your forks? Make sure they are not tweeked. You may want to loosen the triple clamps and reset them.

I had a KZ650 that would do that, drift off to the left. It ended up being a very slighty bent frame, nothing major.

Welp...
I adjusted the damper on the rear shocks, they were at 2, tried 3 and four out on the highway. 4 turned out the best feeling at 50-75mph.
At slow speeds it still feels like it wants to oversteer given the slightest anything. I experimented at 10-20mph. Just a lean of my body, or slight push on the handle bars felt like it wanted to take off that way.

I did the suggested front fork hang/unsprung adjustment. Both forks are precisely the same sticking up past the top brace- about 1/4" higher measured off the fork tube body, not the air or nut housing.
IF the tires are "ok" (brand new dunlop 404's..never been a fan of dunlops and now subconsciously regret having them put on), it may be bad rear shocks (swing arm felt ok today on the jackstands) but I dont think so, or could be the whole front fork is adjust too loosely? Reading the shop manual had warnings about too tight, or too loose.
Could too much air in the front tire be doing this? I've tried 30-34. I had run 26/28 with the metzners, but I've read quite a bit about low pressure and heat causing failure, so..figured a bit more air than I've run in tires in the past.
And the input is MUCH appreciated.

just a shot in the dark he said it has a drive shaft

nature of the beast?

just sayin

just a guestion when you did the run down the hill were you in your lane or the center of the road?
if you were in your lane go back and try the oppisite lane of corse make shure nothing is comeing and see if it goes the same way or pulls right.
I live in maine and are roads are crowed pritty good and it make a differnt witch side of roadyour on to witch way it goes becouse your not square to the road surfice

just my two cents