MT09 (FJ) Tracer Steering Wobbling

[scuff]

Unfortunately, incorrectly adjusted steering bearings would be a failure for an MOT test. And possibly an offence of using a vehicle in a dangerous condition, as it would be outside the specs of the design and manufacture.
In order to get some resistance on the bearing, they would have to be over tight.

[Guest rszk]

I remedied mine by softening front preload, increased rebound dampening, rear shock, increased rear preload and rebound dampening. No wobbling on aggressive riding now.
Front: 17.2mm preload, 10 clicks rebound
Rear: 5 preload, 1/2 turn from maximum rebound
180 lb rider

[thruster8999]

I am going to try your settings. I went the other way with a harder front end. Maybe softing it up will help for now.

[skipperT]

Replacing the steering head bearings with AllsBalls bearings will also make a BIG improvement. Because they are a tapered timkin bearing, they can be over torqued a bit and still move smoothly.
 
Cheaper than a steering stabilizer.
 
-Skip

[scuff]

So why hasn't everyone done it skip.
On the contrary, taper bearings are prone to more wear and seizure if incorrectly adjusted, but if fitted properly will improve life over roller bearings as the tapering resists lateral movement better than ball bearings.
And you still can't adjust them for the conditions etc....
I know I'm not going to convince you all, so I'll leave you make your own choices.
 

[mjsracing]

Unfortunately, incorrectly adjusted steering bearings would be a failure for an MOT test. And possibly an offence of using a vehicle in a dangerous condition, as it would be outside the specs of the design and manufacture. In order to get some resistance on the bearing, they would have to be over tight.

Perhaps it is possible to increase the preload on the steering bearings (by "tightening" the nut) such that there is noticeable stiction (static friction) with no concern for bearing or race damage? 
Clearly too much preload on the bearings is not good.

[milton]

For those interested, I just got a message from GPR :
 
Quote
Just finished a kit for the fj09. Will have ready to ship early next week
Unquote
 

[skipperT]

So why hasn't everyone done it skip. On the contrary, taper bearings are prone to more wear and seizure if incorrectly adjusted, but if fitted properly will improve life over roller bearings as the tapering resists lateral movement better than ball bearings.
And you still can't adjust them for the conditions etc....
I know I'm not going to convince you all, so I'll leave you make your own choices.

 
 
Probably due to availability of the bearings (not listed yet ) and difficulty in replacing them. It's not exactly an easy task. Most shops would charge 2-3 hours probably and the parts are only $40-60.
 
It's easier to complain on an Internet forum and try simple things like suspension setting (which DO help) than to swap the steering bearings.
 
It's also not as sexy as a steering damper....
 
-skip

[mathprof]

When I checked my front end it stayed where I put already.
Its not surprising that dirt bike geometry is radically different from street bikes.
Sorry if I stirred the hornets.

[kayotte]

For me: 170lb rider
 
Front: 15mm preload, 8 clicks rebound
 
Rear: factory
 
Seems it`s perfect, but I`m still experimenting. 
 
 
 

[jimf]

FWIW, with the Yamaha hard bags on the bike it wobbles a hell of a lot easier than it did without them, when riding at 70+mph; just give the bars a little push and it'll wobble away for a bit.  The difference versus no luggage was quite obvious.  It's not hard to control, but a bit disconcerting.
 
I'm more or less of the opinion that the extra weight on the rear changed the geometry just enough to cause this.  It certainly pushed the rear out of the "this feels reasonably good" range into the "this feels a bit overloaded" state.  I've not yet bothered to add some rear preload to compensate, on account of I'm both busy and lazy :-), but that's the plan as soon as I can find time to experiment.  That would jive with the fixes several others have mentioned.  I'm a little surprised that adding more rake/trail makes it less stable, if that's what's going on.  Two-wheeler dynamics certainly aren't intuitive.
 
I've never before had a bike whose behavior changed so much just from adding mostly empty luggage, eesh.
 
 

[deersSlayer]

FWIW, with the Yamaha hard bags on the bike it wobbles a hell of a lot easier than it did without them, when riding at 70+mph; just give the bars a little push and it'll wobble away for a bit.  The difference versus no luggage was quite obvious.  It's not hard to control, but a bit disconcerting. 
I'm more or less of the opinion that the extra weight on the rear changed the geometry just enough to cause this.  It certainly pushed the rear out of the "this feels reasonably good" range into the "this feels a bit overloaded" state.  I've not yet bothered to add some rear preload to compensate, on account of I'm both busy and lazy :-)

Takes less than 5 minutes to change the rear preload. What is your preload set to?
It's probably too little for you even without luggage.
 

[wessie]

I was quite happily cruising on the French Autoroute at the 110[0] speed limit with my Kappa K40 cases without any stability issues. Each pannier had a 10kg load or so. Seemed to handle quite well in the twisties in the Vosges mountains too.
 
[0]I think they meant 110kph but I forgot to flip the display from mph

[johan]

I was quite happily cruising on the French Autoroute at the 110[0] speed limit with my Kappa K40 cases without any stability issues. Each pannier had a 10kg load or so. Seemed to handle quite well in the twisties in the Vosges mountains too.  
[0]I think they meant 110kph but I forgot to flip the display from mph

I once tested the 130kph speed limit under similar conditions on a French motorway after I made a brief stop and wanted to catch up with you lot, no stability issues and I had all the luggage on. Was the trip from Beaune to Alsace.

[jimf]

FWIW, with the Yamaha hard bags on the bike it wobbles a hell of a lot easier than it did without them, when riding at 70+mph; just give the bars a little push and it'll wobble away for a bit.  The difference versus no luggage was quite obvious.  It's not hard to control, but a bit disconcerting. 
I'm more or less of the opinion that the extra weight on the rear changed the geometry just enough to cause this.  It certainly pushed the rear out of the "this feels reasonably good" range into the "this feels a bit overloaded" state.  I've not yet bothered to add some rear preload to compensate, on account of I'm both busy and lazy :-)

Takes less than 5 minutes to change the rear preload. What is your preload set to? It's probably too little for you even without luggage.

I agree, it probably has always been too little, but I was reasonably happy with it with just me.  With the loaded soft luggage it was clearly too soft, but I liked having the lower seat height :-).  There's no excuse for not fixing it now.  I'll get right on that (after watching today's stage of Le Tour; priorities!).