Front End Vibration

[MrM0t0]

My '08 AE has a bad vibration in the front that starts at about 85 and peaks at 90 then never goes away until I bring it back down below 85 again. (This is per the Zumo 550 not the speedo.) It's done it through 2 sets of PR2s, but didn't do it on the 1st set. Is there anything besides an out of balance tire that can cause this?

I'm doing a track day on 7/20 and really want to sort this out by then. I have a brand new set of PR2s waiting to put on.

 

[MrM0t0]

My '08 AE has a bad vibration in the front that starts at about 85 and peaks at 90 then never goes away until I bring it back down below 85 again. (This is per the Zumo 550 not the speedo.) It's done it through 2 sets of PR2s, but didn't do it on the 1st set. Is there anything besides an out of balance tire that can cause this?

I'm doing a track day on 7/20 and really want to sort this out by then. I have a brand new set of PR2s waiting to put on.

 

[ahchiu]

Check your steering head bearings torque.

 

[garyahouse]

Is this an up and down shaking, typical of a tire out of balance? Does it get worse as speed increases above 90? I think you're implying that it tapers off after 90, but doesn't go away. Or is this more of a back and forth shaking of the handlebars?

I had an awful shaking back and forth in my handlebars from the first day I put my new PR3 on... until the day we took it off and replaced it with a new PR2. It occurred between 35 and 50. We rebalanced the tire figuring that might be the problem but to no avail. Later on, with a new tire, problem solved. From what I've read, occasionally a tire is just defective from the factory: out of round, out of whack, out to lunch: who knows. It does happen, though it's rare. But what you're describing sounds different. I'm wondering about wind turbulence. Do you have a top box on your FJR? An oversize windshield? Another thought: ever service the steering head bearings?

Gary

darksider #44

 

[RaYzerman19]

How much weight does it take to balance.... my wheels by themselves are out a whole bunch, so I balance them first before the tires are on. Tires then don't seem to need much to tweak the balance. I'm just thinking that if it takes a bunch to balance, better to do the wheels first. I'm using Metzelers though.....

 

[garyahouse]

If you want to go the extra mile to get it just right, spend your time fussing with it once ya get it REAL close. That's where the extra time might indeed accomplish something.

Good luck and keep us posted.

 

[Fred W]

Make 100% sure that the tire is properly, concentrically seated on the rim. There is a little tiny rib in the sidewall right along the rim edge that can be visually used to see if the bead is properly and evenly seated. If it is not right and the tire has been on for any length of time, then that tire may have worn out of round so even if you set that right you may still experience vibration.

Might also want to check the front wheel for true both axially and radially next time you have the tire off. But my bet would be on the tire in some fashion.

 

[Aasland]

From what I've read, occasionally a tire is just defective from the factory: out of round, out of whack, out to lunch: who knows. It does happen, though it's rare.

Yep, I've seen this too. I change tires for my close group of friends, maybe 8-10 sets a year, and only three fronts proved to be defective (they were all Avon fronts). They were fine going on, but within three thousand miles they were unusable and replaced.

Interestingly, I the Contimotion front I have now was OK for a few thousand miles than needed to be re-balanced; I don't think any weights fell off; I actually had to remove some. Thus I think some tires can wear "funny".

 

[C&C]

I would check the steering head bearing and also check for wheel run-out (hit any large potholes that might have bent the rim slightly). Also, as above, check for a completely seated tire and/or tire run-out (which can also occur).

 

[MrM0t0]

Is this an up and down shaking, typical of a tire out of balance? Does it get worse as speed increases above 90? I think you're implying that it tapers off after 90, but doesn't go away. Or is this more of a back and forth shaking of the handlebars?I had an awful shaking back and forth in my handlebars from the first day I put my new PR3 on... until the day we took it off and replaced it with a new PR2. It occurred between 35 and 50. We rebalanced the tire figuring that might be the problem but to no avail. Later on, with a new tire, problem solved. From what I've read, occasionally a tire is just defective from the factory: out of round, out of whack, out to lunch: who knows. It does happen, though it's rare. But what you're describing sounds different. I'm wondering about wind turbulence. Do you have a top box on your FJR? An oversize windshield? Another thought: ever service the steering head bearings?

Gary

darksider #44

I have a huge RIfle screen. The vibration seems to be back and forth, but I'm not sure how to discern it from an up and down motion. I have a top box, but it does it with or without the box on.

 

[Colin24]

My '08 AE has a bad vibration in the front that starts at about 85 and peaks at 90 then never goes away until I bring it back down below 85 again. (This is per the Zumo 550 not the speedo.) It's done it through 2 sets of PR2s, but didn't do it on the 1st set. Is there anything besides an out of balance tire that can cause this?
I'm doing a track day on 7/20 and really want to sort this out by then. I have a brand new set of PR2s waiting to put on.

I've had off an on problems with vibration like you have described. I cured the problem by getting the Marc Parnell Tire Balancer and balancing the wheels myself.

The shops might have those fancy computer speed balance machines. But you still need someone to take the time to do it right. Its been my experience they don't take the time. In fact the first few tires I had installed after I got the balancer I still had the shop balance the tires anyways just to see what it was like. Both times I had to add an ounce or more to each wheel to actually get the tire balanced. So eventually just stopped having them balance the tires at all and just do it myself now.

Every set of tires I have balanced myself since has been spot on and I have no vibration related issues whatsoever.

Just my $0.02 worth.

- Colin

 

[Bounce]

duplicate threads merged

 

[MrM0t0]

Regarding the steering head bearing theory, I've made a close visual inspection and discovered some minor seepage of grease at both the top and the bottom. I already have a new set of bearings on the shelf I bought to have on hand. Should I change them out based on this grease evidence?

 

[PhilJet09]

I would torque the bearing nut to spec, lift the front end off the ground, slowly rotate the bars from stop to stop and check for notchy movement, especially around the center position. If everything is smooth, then there's no need to change the bearings.

 

[Bounce]

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

 

[Aasland]

I would torque the bearing nut to spec, lift the front end off the ground, slowly rotate the bars from stop to stop and check for notchy movement, especially around the center position. If everything is smooth, then there's no need to change the bearings.

I would suggest removing the forks first.

With the weight of the forks on the triple tree you'll only feel the indents on the upper bearing, while it's the lower bearing that takes the brunt of the impacts, and that carries the weight of the FJR when you're actually riding.

 

[MrM0t0]

New tires resolved this. The front had worn to a point where there was a high point at every sipe. Took 'er out today and she's like warm buddah all the way up to 120.

I am ready for my 1st trackday on 7/20 at Thompson.

 

[ahchiu]

Glad you got it figured out, the PR2 handling goes down hill towards the end.