High speed thumping

[Mike P]

Once I reach triple digits, right at 110mph I start feeling a thumping type vibe/noise whatever it may be. It seems to go away once I hit 130 but if I hold it at 110-ish it never goes away. Nothing else about the bike seems to be out of the norm other than I know I need to re-torque my head steering head.

I checked wheel balance, all was good there.

Any suggestions?

 

[madmike2]

Hmmmmm....tire balance wouldn't fade, but mot of the time would worsen.

Does this happen on different roads? There are those roads that have seams and that pattern can be transmitted through the forks.

 

[Okie]

When you checked balance, was that static only? It sounds like a dynamic balance problem. It tends to show up at higher speeds and will cause a wheel to wobble and pulse. You might try taking it to a shop that can check and correct it for you.

 

[radman]

Adrenaline. Do it more often, you'll get used to it.

 

[GalaxyBlue]

Are you running BT 021's by chance? I had a similar experience when mine were worn down. The only difference is once the vibe/thumping came in, It only worsened with more speed.

 

[Mike P]

When you checked balance, was that static only? It sounds like a dynamic balance problem. It tends to show up at higher speeds and will cause a wheel to wobble and pulse. You might try taking it to a shop that can check and correct it for you.

Checked both ways.

 

[Mike P]

Are you running BT 021's by chance? I had a similar experience when mine were worn down. The only difference is once the vibe/thumping came in, It only worsened with more speed.

That I am, but both only have about 3k on them, no cupping on the front, no squareness on the rear.

Only possibility would be flat spots on the front from wheelies but I should be able to feel it at lower speeds if that is the case.

 

[Wicked Webby]

As far as the tire mis-balance theory,

If it isn't the tire...

Even if it balance's out ok, could be a specific heavy spot in the rim itself that is causing issues.

I once had a similiar issue before with my ZX10R.

The cure was that I located the heavy spot on my rim (marked it) and always located my balance weights opposite to it. Also, this helped me use less weights.

WW

 

[Kaelaria]

I'm stuck on a Sportster while my FJR is getting the tranny redone, so I don't remember what 110 is like...but I would guess you need a new tire.

 

[rbentnail]

https://www.fjrforum.com/forum//index.php?showtopic=111601

A longer discussion.

 

[rhody]

Once I reach triple digits, right at 110mph I start feeling a thumping type vibe/noise whatever it may be. It seems to go away once I hit 130 but if I hold it at 110-ish it never goes away. Nothing else about the bike seems to be out of the norm other than I know I need to re-torque my head steering head.
I checked wheel balance, all was good there.

Any suggestions?

Mike P,

There is an identical thread, "High Speed Thumping" started by Kirrilian, that I posted to on the second page, and maybe with a little Admin help we could somehow get these threads combined. I am glad you are reporting this because you are the third one to notice it, have a look at the other thread and see if any of the suggestions to test ring true to you and let use know. A simple search filtering by member Kirrilian will let you see it.

Good luck.... :blink:

 

[rhody]

https://www.fjrforum.com/forum//index.php?showtopic=111601A longer discussion.

Sorry rbentnail, didn't mean to steal your thunder, I scanned most of the posts but must have missed yours.

 

[Canadian FJR]

Bent rim ?

Canadian FJR

 

[Checkswrecks]

Once I reach triple digits, right at 110mph I start feeling a thumping type vibe/noise whatever it may be. It seems to go away once I hit 130 but if I hold it at 110-ish it never goes away. Nothing else about the bike seems to be out of the norm other than I know I need to re-torque my head steering head.
I checked wheel balance, all was good there.

Any suggestions?

Obviously stay above 130. Duh <_<

 

[BugR]

I have the same problem except that it occurs on my back between my shoulder blades and sometimes the helmet.

Another coincidence is that the wife is always on the back when this occurs.

As the speed rises above 160 (Km/h) it stops but only because she has to use both hands to hang on.

(It usually helps to turn off the intercom at the same time while attempting this)

 

[Kirrilian]

I have the same problem except that it occurs on my back between my shoulder blades and sometimes the helmet.Another coincidence is that the wife is always on the back when this occurs.

As the speed rises above 160 (Km/h) it stops but only because she has to use both hands to hang on.

(It usually helps to turn off the intercom at the same time while attempting this)

I laughed out loud at work from this one, hehe

 

[Kirrilian]

https://www.fjrforum.com/forum//index.php?showtopic=111601A longer discussion.

Sorry rbentnail, didn't mean to steal your thunder, I scanned most of the posts but must have missed yours.

Thats because it was my thread not theirs

 

[rocketman]

First check with a cardiologist.

Then a mechanic.

 

[Bounce]

My guess? The co-rider is trying to get your attention.