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General Category => Yamaha FJ1100 / FJ1200 Running Problems => Topic started by: las1200 on January 14, 2011, 07:39:45 PM

Title: steer wobbles
Post by: las1200 on January 14, 2011, 07:39:45 PM
Hi FJ's

Please advice.
Today noticed my FJ steer wobbles alot in road irregularities if i i'm not gripping steering. It happens at different speeds.
Never noticed this before.
Tire pressure? It looks ok.
Front suspension problem?

thanks
Title: Re: steer wobbles
Post by: racerman_27410 on January 14, 2011, 08:27:51 PM
time to adjust the steering head bearings

front wheel off the ground

with handlebars centered give a little push sideways

handlebars should fall to the stop but not bounce back off the stop

if it bounces tighten them up

dont tighten them too much or you can open a whole nuther can of handling worms.

good time to check and make sure there is no notchiness in the movement of the bars.

KOokaloo!


Title: Re: steer wobbles
Post by: andyb on January 14, 2011, 09:25:39 PM
Also happens with worn front tires.  Also can happen with new tires if they're an aggressive profile.

Title: Re: steer wobbles
Post by: SlowOldGuy on January 14, 2011, 09:44:42 PM
Be sure and check everything Frank mentioned.

But, every time I had/have this problem, it's 100% a worn or badly cupped front tire.  It's most noticeable during decelleration from about 50 MPH with my hands off the bars.

Some tires can even cause this when new.  My best example is the now discontinued Metzeler MEZ2.  It had a somewhat zig-zag center tread that cause a pronounced wobble from the day it was installed.

DavidR.
Title: Re: steer wobbles
Post by: Travis398 on January 15, 2011, 07:30:40 AM
+1 on the front tire. my bike did that for a little while but went away after a couple hundred miles.
Title: Re: steer wobbles
Post by: weymouth399 on January 15, 2011, 08:11:29 AM
Wasn't that a high speed wobble you had Travis :dash1: during the NEFJR.
It couldn't have been a result of Nobby or Eric MAKING you go that fast :rofl:
Then when you slowed down it doesn't do it anymore, huh magine that.
Bob W

If your tire is slightly cupping, you can take a belt sander to it carefully to round off the square parts.
80 grit or less, it will surprise you how well it works.
I have done it to get a little more out of a tire, can we say (cheap basterd)

Bob W
Title: Re: steer wobbles
Post by: carsick on January 15, 2011, 11:43:19 PM
Bob, I can understand DOING these type of things, but admitting and recommending them? You've been watching Red Green again.
Title: Re: steer wobbles
Post by: weymouth399 on January 16, 2011, 06:36:43 AM
No just tried to get a 1000 more miles out of my stock tires.
It was more of a test, we profile our racecar tires ice tires that way and I wanted to see if it would work. (like a champ)
Bob W
Title: Re: steer wobbles
Post by: las1200 on January 17, 2011, 04:57:28 PM
ok, doing bearings test and see what happens.
tire looks ok, pressure ok (35psi-2.5bar) and no obvious degradation.
it's a dunlop sportmax, any comments on these tires?

do I need special tool to loosen and tight stem nuts?
by the way, how do you usually maintain front whell up for maintenance (long periods)?

thank all the for help! :good2:
Title: Re: steer wobbles
Post by: RichBaker on January 17, 2011, 05:32:00 PM
Tire pressure is LOW.... should be 38f 42r, unless you're a skinny little guy.
Title: Re: steer wobbles
Post by: Harvy on January 17, 2011, 06:05:59 PM
Quote from: RichBaker on January 17, 2011, 05:32:00 PM
Tire pressure is LOW.... should be 38f 42r, unless you're a skinny little guy.


Rich....I could take offence at that.......hahahha.

Us skinny little guys like 36F/42R.


Harvy
Title: Re: steer wobbles
Post by: Harvy on January 17, 2011, 06:23:11 PM
Quote from: las1200 on January 17, 2011, 04:57:28 PM

do I need special tool to loosen and tight stem nuts?
by the way, how do you usually maintain front whell up for maintenance (long periods)?

thank all the for help! :good2:

Stem bearing nut..... a big spanner is all you need..... The manual has torque numbers, but I have always pulled it down as tight as I can (so the bearings are seated, and then loosen it so that I have full movement l-r with no bounce back......works ok for me.
Remove the handlebars, remove the acorn stem nut on the top of the top triple, remove the top triple, remove the top bearing nut/washer. Adjust the bottom nut as above. Re-assemble it all.

Front wheel........ remove the chin fairing, place a block of wood across the header pipes forward of the centre of balance and jack it up so that the front wheel is just off the ground, but not high enough that you are either grounding the rear wheel, or trying to lift the whole bike off the centre stand.

HTH
Harvy
Title: Re: steer wobbles
Post by: markmartin on January 17, 2011, 07:14:10 PM
Quote from: Harvy on January 17, 2011, 06:23:11 PM
Quote from: las1200 on January 17, 2011, 04:57:28 PM

by the way, how do you usually maintain front whell up for maintenance (long periods)?


Front wheel........ remove the chin fairing, place a block of wood across the header pipes forward of the centre of balance and jack it up so that the front wheel is just off the ground, but not high enough that you are either grounding the rear wheel, or trying to lift the whole bike off the centre stand.

HTH
Harvy



Would this work?  I had to put a scrap piece of wood (2"x8")  under the center stand so I could 'teeter- totter' the back end down while an assistant shoved the stand under the frame. This should hold the front end up. (ignore the scrap wood under the rear tire--I was working on my shock in that pic, so holding the rear wheel up in the process)

(http://fjowners.com/gallery/1/150_17_01_11_7_01_19_1.jpeg)

(http://fjowners.com/gallery/1/150_17_01_11_7_01_12_0.jpeg)
Title: Re: steer wobbles
Post by: Harvy on January 17, 2011, 07:45:02 PM
Don't see why not Mark..... I recon you could support a battle ship with that.  :i_am_so_happy:

Harvy
Title: Re: steer wobbles
Post by: weymouth399 on January 17, 2011, 07:50:00 PM
Mark great carpentry skills, who knew :biggrin: just some scraps lying around, humble too :sarcastic:
Bob
Title: Re: steer wobbles
Post by: Travis398 on January 17, 2011, 08:21:22 PM
Dude I have the same miter saw in that first pic :rofl:
Title: Re: steer wobbles
Post by: las1200 on January 18, 2011, 11:21:48 AM
who could ask for more?
great pics, mark.
1 pic=1000words
thank's guy's!