FJRiders.com

He all. Employing the collective wisdom.

My bars and front forks are vibey at high speeds, like around 90-100+ mph. (On the track. )

My wheels are in balance. I have not tightened my head bearing or replaced wheel bearings and now at 28k miles.

I do notice that the bottoms of the fork legs seem to be bouncing front to back at speed.

I have .95 racetech springs and 7.5 weight oil. Compression dampening around 9 clicks and reb about 8. I have toyed with the clickers a bit, but doesn't change the vibing.

I realize the vibes are only at high speeds, but I feel like the fork legs shouldn't be wiggling the way they are. I'm wondering if maybe switching to the higher weight oil has affected high speed dampening (i.e. a lower weight oil would allow more fluid movement when suddenly jarred, thereby eliminating the vibe without allowing fork dive).

Could this just be wheel bearings? Seems like I'd notice vibes at lower speeds to. Ideally, the ride would still be completely smooth even at high speeds. While it isn't unbearable as is, it's definitely not perfect.

Thanks in advance.

My first step would be to check the head bearing torque. Lots of other threads on how to do that.

Bent wheel maybe? Might try spinning it by hand carefully looking for any out of round run out.

What shield are you running? At that speed, a variety of things can contribute to suspension anomaly. I think you're looking in the most likely area, but not necessarily the only area that could create that symptom. The amount of air you're pushing can affect the very trim of the bike, as you well know.

Following.

Tires or tire pressure. Windshield. And a distant third, the steering head. Start by confirming that your tire pressures front and rear are in the range of 40 - 42 psi.

Put your bike on the center stand. Sit facing the bike with the front wheel off the ground. Put your hands on the bottom of the forks and push and pull, there should be no play. From the same position turn the forks from full left to full right, there should be no notchiness or binding. Your steering head is good to go if it passes these tests.

If your windshield is OEM, it's not the problem.

Given the low miles on your bike I doubt the problem is the bike. Have you hit or run over anything of significance? Have you dropped your bike, even at zero mph? Picking up the bike can tweak the front forks. Since the fork fluid has been changed, is there an assembly issue? Are both forks the same height in the triple tree?

Loosen the four front fork Allen screws and loosen the axle then tighten it back up following the Yamaha procedure for tightening the axle and the four Allen screws.

As NTXFJR says, check the front rim for run-out. I hold something like a pencil against the front fork, close to the wheel and slowly spin the wheel and look for any gap variation, there should be zero variation. While there check the tire sidewall bead line, it should be equal on both sides and even all the way around the wheel on both sides.

If the problem remains it is highly probable you have a tire issue. If your bike had more miles on it I would mention that it is possible for the rear suspension to cause front wobbles but given your low miles it's not likely.

ionbeam wrote: ↑Thu Jan 02, 2020 7:31 am Loosen the four front fork Allen screws and loosen the axle then tighten it back up following the Yamaha procedure for tightening the axle and the four Allen screws.

Since I paid my 2014 FSM forward when I got rid of the 2014, and don't have one for the 2018 yet, could you share the order you reference above, for this n00b (who knows, the OP may find it useful as well)? Please and thank you.

At higher speeds, the imperfections will become more evident..... airflow over the arms, etc. (tuck in, lean forward over the tank, see if body position makes a difference, remove the saddlebags and definitely the top box if you have one... I assume you do this for the track anyway).
I also suggest loosening the axle and pinch bolts and jouncing the front suspension to assure the best alignment. Retorque axle nut, then the pinch bolts. Out of round tire or excessive runout wheels are other contributors... fork springs and damping settings seem OK to me, don't think 7.5 oil is much of a factor.... bearings OK unless notchy or noisy.... slight imbalance of tires at that speed will reveal itself... how were they balanced, dynamic or static?
Rear suspenders can make a difference also..... if it's the stock rear, all you've got is a rebound damper... does it make any difference if set on Hard preload?
I would put a jack under the headers and check for any play in the steering head, but the weight of all that makes it difficult... turn the bars side to side see if any noticeable bearing issues... I would retorque, but on the final step, go to 15-18 ft. lbs.... check side to side drag, the old fashioned way (IMHO Yammy's 13 ft. lbs. is on the light side).
The other thing about this is, if you do a whole bunch of things all at once you won't know what the cause is....

bill lumberg wrote: ↑Thu Jan 02, 2020 8:55 am

ionbeam wrote: ↑Thu Jan 02, 2020 7:31 am Loosen the four front fork Allen screws and loosen the axle then tighten it back up following the Yamaha procedure for tightening the axle and the four Allen screws.

Since I paid my 2014 FSM forward when I got rid of the 2014, and don't have one for the 2018 yet, could you share the order you reference above, for this n00b (who knows, the OP may find it useful as well)? Please and thank you.

Not at home at the moment, but if memory serves right, as you are sitting in front of the bike looking back at it, you tighten the left screw first, then the right screw. This is true for the set screws on both forks. Someone correct me if I'm wrong.

bill lumberg wrote: ↑Thu Jan 02, 2020 8:55 am

ionbeam wrote: ↑Thu Jan 02, 2020 7:31 am Loosen the four front fork Allen screws and loosen the axle then tighten it back up following the Yamaha procedure for tightening the axle and the four Allen screws.

Since I paid my 2014 FSM forward when I got rid of the 2014, and don't have one for the 2018 yet, could you share the order you reference above, for this n00b (who knows, the OP may find it useful as well)? Please and thank you.

John d wrote: ↑Wed Jan 01, 2020 11:10 pm My first step would be to check the head bearing torque. Lots of other threads on how to do that.

https://www.fjr-tips.org/maint/shb/shb.html

Pay particular attention to the "tighten, loosen, re-tighten" process of seating everything at the end.

The pinch bolt sequence is because as you tighten one, the other will loosen, so eventually, you need both to be the same.

Addendum to steering head.... you do this with the wheel still mounted to keep the upper and lower triple tree in alignment when you reinstall the upper triple tree. A better tool for the torquing is a castellated affair, which you can make from a 36mm socket or buy one on ebay already done. This is the pic of mine, made way back by a forum member somewhere.... much preferred over the hook style. You don't need all 6 castellations, 4 will do ya.
Ebay listing...... https://www.ebay.com/itm/Yamaha-FJR-130 ... Sw06BdyWNu

Also, the big nut..... 85 ft. lbs is overkill..... 75-ish is plenty good.

I'm in the camp of "bent front wheel" as I have been down this road a few times. Once right before my trip out to Cali this past fall. My vibration was also at 80-85+ mph.

jwilly wrote: ↑Thu Jan 02, 2020 2:54 pm I'm in the camp of "bent front wheel" as I have been down this road a few times. Once right before my trip out to Cali this past fall. My vibration was also at 80-85+ mph.

Was that after the Smoky 500 dual-sport jaunt with yer FJR, or after the you jumped a few buses?

This thread is very interesting. My 15 has incurred a similar vibration at the higher speeds of 85 and becomes worse as speed increases. I did all the normal things like re-balance, check pressure, and changed tires. The problem was mitigated some, but not cured. I will be for looking for a resolution for the OP and hopefully be able to cure my own wobble issues. Thanks for bringing this to light.

Cav47 wrote: ↑Thu Jan 02, 2020 4:35 pm ...My 15 has incurred a similar vibration...I did all the normal things...but not cured. I will be for looking for a resolution...

Youse guys are starting to scare me. Is this a ES thing or all FJRs in this Gen group?

My ES USD (Upside Down) forks are flush with the top of the triple tree per the FSM. Is this a USD thing?

Mine is a ES. I remove and have a local guy change my tires. I am willing to bet that my reassembly procedures are faulty. That or steering head is not up to spec.

It is not a balance issue for sure. CraigRegs and I spent an inordinate amount of time balancing the rim and then the tire/rim combo last time. The problem was slightly better, but still noticeable above 80. Not that my FJR ever sees any time over that speed—while not on a closed course.

Let’s be honest, it’s common hitting 100+ when forced to overtake a line of cars. I want the FJR rock solid at all speeds. I smell some tech day items coming on.

I haven't had my 13 up to FJR nominal, I usually just go 45mph on the highways and just wave people around.

But on one of my 04s, I had it up to FJR Nominal...and smooth as butter. I did it a second time on the way back from Kali...this time with a double-plugged tire...still smooth as butta.

ionbeam wrote: ↑Thu Jan 02, 2020 4:50 pm

Cav47 wrote: ↑Thu Jan 02, 2020 4:35 pm ...My 15 has incurred a similar vibration...I did all the normal things...but not cured. I will be for looking for a resolution...

Youse guys are starting to scare me. Is this a ES thing or all FJRs in this Gen group?

My ES USD (Upside Down) forks are flush with the top of the triple tree per the FSM. Is this a USD thing?

For the record, I have an "A" model Gen 3. Ya know the faster one...

jwilly wrote: ↑Thu Jan 02, 2020 5:16 pm

ionbeam wrote: ↑Thu Jan 02, 2020 4:50 pm

Cav47 wrote: ↑Thu Jan 02, 2020 4:35 pm ...My 15 has incurred a similar vibration...I did all the normal things...but not cured. I will be for looking for a resolution...

Youse guys are starting to scare me. Is this a ES thing or all FJRs in this Gen group?

My ES USD (Upside Down) forks are flush with the top of the triple tree per the FSM. Is this a USD thing?

For the record, I have an "A" model Gen 3. Ya know the faster one...

Ahh, an equal opportunity wobble, no FJR left out. So far mine seems OK. During riding season I hit that kind of speed daily on my limited access race track.

To the OP, what does the front tire look like in terms of wear? Is there even the slightest hint of scalloping or cupping?