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[Dan_Lockwood]

I know some are worse than others, but am I seeing a pattern here???

I have an '09 SERG and it has had the neck bearings adjusted twice, once at 1k mile check up and next at the 5k check up.  Tank slappers stories seem to have gone down quite a bit since the new '09 frame, but before that both EG and RG bikes had the same issues with wobble, mainly high speed.

Now it seems that the only time we hear about wobble is on RG bikes and most are at lower speeds and most seem to be on decel rather than constant speed.

At about 40 mph on my SERG, if I let go of the handlebars (I know I should not do that, but...) the bike will go for maybe a few seconds fine and then the bars will start to shake and just get worse until I grab them or I'm sure if I did not grab them the bike would flip from the violent wobble.

So do you see a trend on the RG's over the EG's for front end wobble?

I know the drop away setting has been decreased a couple times since '09 on the RG's over the EG's.  Why should the drop away settings be different between RG's and EG's?  They both have the fork angle and trail etc.  I know that the weight of the EG fairing is a possible stabilizer of sorts and the RG's of course just have the forks themselves to deal with.

Any thought on RG specific wobbles compared to the EG's?

[JCZ]

I made the same observation back in 09, on this forum.  There has been two or three electra glide of one model or another but nothing compared to the Road Glide models, since the new frame.  Just not sure why it would be more specific to the Road Glides.

[Dan_Lockwood]

JC, there has to be something that's different, but what???

Back several years ago there was some talk about steering stabilizers and I believe Hoist had a couple trying them out.  I finally got in touch with him way back when and he still had not tried anything. 

Does the Tri-Glide come with a stabilizer?  I thought somewhere I read they did.

There has to be a more reliable fix than just keep tightening the neck bearings.

If I designed a car with "0" caster, it would wobble all over the place.  If I add caster into the equation the wheel starts to track and "follow" rather than trying to lead.  I've not read up on rake/trail etc, but I have to think that we would be more than willing to give up a bit of the "power steering" effect of the current HD neck fork geometry for a slightly stiffer steering feel, but a whole lot better tracking and less wobble.

I would imagine that a Bonneville streamliner has a bit different rake/trail than our touring bikes, just for stability.

Sometimes I feel like I have a loose wheel shopping cart hanging out front instead of a well designed and stable HD.

If anyone has any thoughts on possibly triple tree changes or have done changes, what's out there and how did they work?

Right now I'm just rambling and thinking outload, or with my fingers...

This is an OPEN FORUM so let the ideas and thoughts fly.      

[timo482]

hd baggers have something like 6" of trail now.

its quite a lot - wobble is the same wobble that grocery carts get & its most likely from something loose, something moving, too free a front end, or some tire harmonic.

but its nasty to have a wobble

to

[Indenial]

Try Dyna Beads?  May not help, but it won't hurt and is a cheap fix if it works.

[North Star]

An HD mechanic told me the the neck bearings need to be torqued different (more I think) on the RG than on the batwings.

I think not all mechanics realize this, and just torque it to the lower batwing-fairing bike specs- not tight enough.

[Dan_Lockwood]

An HD mechanic told me the the neck bearings need to be torqued different (more I think) on the RG than on the batwings.

I think not all mechanics realize this, and just torque it to the lower batwing-fairing bike specs- not tight enough.

That's true that they need to be tighter than EG bikes.

But WHY should they need to be different if in general the EG's don't have the same low speed wobble as the RG's with a lesser fall away tightness spec?

[grc]

That's true that they need to be tighter than EG bikes.

But WHY should they need to be different if in general the EG's don't have the same low speed wobble as the RG's with a lesser fall away tightness spec?

Two different things involved.  One is the torque on the stem nut, which Harley had found to be too low which allowed the nut to loosen and affect the actual preload.  That was addressed in a service bulletin several years ago, but you have to rely on the technician to torque it to the new correct spec and not the old incorrect spec.  Then you have the actual difference in the number of swings when doing the fall away test.  That particular test is a very imperfect way to measure actual bearing preload.  A better method would involve measuring the preload directly by measuring the torque required to rotate the fork from side to side.  Similar to checking preload on something like a steering gear on a car if you're familiar with that.  For whatever reason, Harley uses the imperfect swing test that is highly dependent on the mass of the various stuff attached to the forks as well as any binding from things like wiring harnesses and cables/lines.  A Road Glide fairing isn't attached to the forks and doesn't rotate with them, so there is a large difference in the mass being rotated between the batwing bikes and the RG's.  Thus the difference in the swing test specs.  Initially I got the impression that Harley mistakenly used the EG specs on the RG's, thus nearly everyone initially had the wobble.  Many dealerships did the same thing.  Thus the need to release the service bulletin detailing the latest swing specs and stem nut torque.

Considering the fact that those changes were made back in 2009, there should be no excuse for the problems to continue beyond the 2009 model year.  Obviously they have, so either Harley's process control still really sucks, or they have another possible cause they haven't found and identified yet.  


JMHO - Jerry

[Dan_Lockwood]

Two different things involved.  One is the torque on the stem nut, which Harley had found to be too low which allowed the nut to loosen and affect the actual preload.  That was addressed in a service bulletin several years ago, but you have to rely on the technician to torque it to the new correct spec and not the old incorrect spec.  Then you have the actual difference in the number of swings when doing the fall away test.  That particular test is a very imperfect way to measure actual bearing preload.  A better method would involve measuring the preload directly by measuring the torque required to rotate the fork from side to side.  Similar to checking preload on something like a steering gear on a car if you're familiar with that.  For whatever reason, Harley uses the imperfect swing test that is highly dependent on the mass of the various stuff attached to the forks as well as any binding from things like wiring harnesses and cables/lines.  A Road Glide fairing isn't attached to the forks and doesn't rotate with them, so there is a large difference in the mass being rotated between the batwing bikes and the RG's.  Thus the difference in the swing test specs.  Initially I got the impression that Harley mistakenly used the EG specs on the RG's, thus nearly everyone initially had the wobble.  Many dealerships did the same thing.  Thus the need to release the service bulletin detailing the latest swing specs and stem nut torque.

Considering the fact that those changes were made back in 2009, there should be no excuse for the problems to continue beyond the 2009 model year.  Obviously they have, so either Harley's process control still really sucks, or they have another possible cause they haven't found and identified yet.  


JMHO - Jerry

Jerry, thank you very much.  Having more mass does increase the flywheel action and stopping that will require more "swings" to do so.  I understand that.  I have always thought that cables on a warm day will allow more ease of swing than on a cold day.

This whole steering head preload is WAY too subjective for my tastes.

As an example when setting the preload on a rearend pinion gear, it's measure in inch pounds and it takes about 20 inch pounds to turn the pinion when the crush sleeve is set correctly.  That is a spec that everyone seems to be able to understand and comply with.  Something like this should be use on the HD steering head, but having access and the means to turn it could be an issue.  You still will have the cables and wiring to contend with no matter what they do.

But really, couldn't some of this be corrected by changing the fork geometry?  I could see this giving the head bearings a lot wider range in being "tight enough".  Also adding dampers of some sort would be a upgrade.  I remember the simple one from back in the '50s and '60s with the knob sticking up out of the steering head that you just tweak down a bit.  It was a friction device, but it worked.

I'm still confused why we still have all the RG issues and seem to have no EG issues.

[petewerner]

The crush tube is too soft and allows setup to soften. That is my observation on this issue with my bike. I also wonder about fork flex being part of the base issue and the violent head shake??

[petewerner]

Are the trip trees the same on RG and SG? I thought the SG's were conventionally laid out with the fork tubes being forward from pivot point, while the RG's have the fork legs trailing the pivot point... Any SG people to verify or correct my thoughts here?

[2018_FLTRXSE]

Are the trip trees the same on RG and SG? I thought the SG's were conventionally laid out with the fork tubes being forward from pivot point, while the RG's have the fork legs trailing the pivot point... Any SG people to verify or correct my thoughts here?

All the touring bike's trees are rear of the pivot point

[Dan_Lockwood]

The crush tube is too soft and allows setup to soften. That is my observation on this issue with my bike. I also wonder about fork flex being part of the base issue and the violent head shake??

I used the crush sleeve as an example in the Ford rearend, but in the bikes I don't think there is anything between the two inner races in the center.  I think there is only the upper washer nut assembly.  So one could just tighten it to the point the fork would not turn.

[Dan_Lockwood]

All the touring bike's trees are rear of the pivot point

I'm not sure when the change to the trailing forks took place.  I do know that the forks on my '76 FLH are in front of the steering head.

When I bought my first new HD in '08, a SERK Annie, I went to a dealership for a HD test ride day and road a new RK to see what I was getting myself in for.

I had ridden the '76 FLH for several years and was used to it, but let me tell you that if you're in a parking lot and just loosen your grip on the bars, the frontend will drop to either side just like you were trying to balance a teeter totter.  Once you got up to speed it was okay.  But under 20 mph it was and still is a handful.

The RK I rode that day seemed like it had power steering.  It was SOOOOO easy to handle in a slow speed situation.  On the road it was very nice as well.

I'm sure the slow speed handling has everything to do with the position of the forks being behind the steering head.

That being said, I'm not sure how you would tighten the steering head bearings on my old FLH.  If you tried a fall away the fork would just drop to either side and stay there, just a big thud is all you would hear.  I'm sure I tightened them per the manual at the time, but I cannot right now remember how I did it.

I agree with lots of others here that there is an inherent design flaw with the touring frame geometry, '09 and later as well as '08 and earlier.  Yes, tightening the head bearings will take care of the problem, but they're still relying on a preload to stop this wobble.  The steering head should have a certain amount of positive stability designed in, not "fix" it with preloading the head bearings.  There should be no reason why two side load sealed for life roller bearings snug fit into the head shouldn't do just fine and just change them out every 50k miles as maintenance.  There would be NO adjustments at all.

Cars correct for stability with positive caster.  More positive caster creates better tracking stability and slightly harder steering as you have to push to overcome the positive caster.  Less caster increases responsiveness in the steering, but too far and it will self steer to either direction and that's deadly.

Sorry I'm rambling here...  I just think there is a solution available that's not being shared by mother Harley!!!

[CumberlandJB]

I had the 40 MPH wobble on decel with my 2012 FLTRXSE.  Over strenuous objections, the mechanic at Longhorn HD cranked down my neck bearing so that it made barely 1 swing.  I told him if he didn't, I would do it on my own.  Now, the wobble is mostly gone.  I actually like the slightly tighter steering better.