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The Rocketman

'09 RT front tire wobble (sort of)

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The Rocketman

Promise....it's not another tire thread....

2009 R1200RT

Have an Avon Storm 3D X-M on front with about 5,000 miles. Michelin PR4GT on rear, almost new from end of last season.

Noticed the other day, at really low speed (under 5 mph) a front wheel "wobble" kind of twisting the handlebars side-to-side. Not under braking; just rolling. Never noticed it before and think I would have.

No noticeable cupping, flat spots or unusual tire wear. Lifted bike up and front end is tight; no brake pads dragging; no warped rotors; no bearing shake or noise. Adjusted ESA to all available settings, and no change. No wobble felt above that speed.

Have a new front PR4GT on the way from Revzilla. Will mount it up and see if it changes things. Tire pressures always either 40/42 or 40/40. Tried dropping the front pressure down to 30, and it felt the same.

New tire will tell if the old tire was the issue or not.

Any opinions?

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w2ge

I’ll bet its the tire..   I had a similar thing on my Aprilia, coasting down coming to a stop sign I would sometimes let my hands off the bars (yeah, yeah, yeah, I know.. whatever )  and would notice a handlebar oscillation around under 40 Mph.  Wasn’t really sure what it was...   but, new set of tires and that was fixed. 

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The Rocketman

That's what I'm assuming too.

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dirtrider
16 hours ago, The Rocketman said:

Promise....it's not another tire thread....

2009 R1200RT

Have an Avon Storm 3D X-M on front with about 5,000 miles. Michelin PR4GT on rear, almost new from end of last season.

Noticed the other day, at really low speed (under 5 mph) a front wheel "wobble" kind of twisting the handlebars side-to-side. Not under braking; just rolling. Never noticed it before and think I would have.

No noticeable cupping, flat spots or unusual tire wear. Lifted bike up and front end is tight; no brake pads dragging; no warped rotors; no bearing shake or noise. Adjusted ESA to all available settings, and no change. No wobble felt above that speed.

Have a new front PR4GT on the way from Revzilla. Will mount it up and see if it changes things. Tire pressures always either 40/42 or 40/40. Tried dropping the front pressure down to 30, and it felt the same.

New tire will tell if the old tire was the issue or not.

Any opinions?

 

Afternoon  Rocketman

 

As mentioned above, usually a tire as dragging  brakes, warped rotors,  can't cause what you are seeing. Probably an internal cord problem or a ply alignment issue. Too slow to be 1st order harmonic so that pretty well leaves tire construction or a tire build issue.

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dduelin

Lift the front wheel clear of the ground and check for noticeable run-out of tire or rim? Agree it's a likely a tire issue.

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The Rocketman

Did raise the front end and nothing unusual noted in tire, rim or rotor. If it were a warped rotor I think I'd feel chattering in the front brake lever, which I don't, and most likely the wobble would be greater at higher speeds, which its not. I'm still leaning towards the tire. Waiting patiently for UPS to pay me a visit.....

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dirtrider
33 minutes ago, The Rocketman said:

Did raise the front end and nothing unusual noted in tire, rim or rotor. If it were a warped rotor I think I'd feel chattering in the front brake lever, which I don't, and most likely the wobble would be greater at higher speeds, which its not. I'm still leaning towards the tire. Waiting patiently for UPS to pay me a visit.....

 

Afternoon  Rocketman

 

Unless you have an extremely warped brake rotor you won't feel it as kick back in the lever as the brake pads will just follow the rotor with fluid displacement across the caliper but no actual fluid displacement outside of the caliper. 

 

Now with a brake rotor thickness variation  you will usually feel a lever kick back as the thickness variation causes fluid displacement outside the caliper then back up the brake line.

 

But none of that applies to your wobble as you only have a single front wheel. With a single front wheel you can not have a brake pull due to a rotor problem (wheel & rotor act as one  with no lateral forces induced),

 

If a brake rotor could cause a wobble or pull in a single front wheel vehicle then a motorcycle with single sided front wheel brake rotor  would  instantly turn a corner every time the front brake was applied.  

 

A high speed wobble or shake can be due to a dynamic wheel imbalance disturbance, or a first order lateral tire disturbance, or a tire problem. 

 

A low speed wobble (usually too slow to become a shake) is usually caused by tire tread interaction with the road surface, or a bent wheel, or mis-shaped/distorted  tire profile. 

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The Rocketman

Got it and understood. New tire #1 got lost yesterday en route from Philadelphia to Long Island. UPS says they have no idea where it is. Tracking number says it never left their hub in NJ, and there's no way to check.

I told them I have a definite idea where it's not.....at my house!!

Either way, tire #2 is on its way via Fedex this time.

We will check the run out on the rotors (just for kicks) and the wheel, prior to mounting the new tire. I'll report back with the results.

And thanks again.

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The Rocketman

I'm pleased to say that a new front PR4GT cured the wobble. A 200 mile shakedown ride today with no issues. All is good in the world again (at least in my little piece of it).

Thanks.

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Joe Mason

I have a 2004 Montauk and have had a shake in front end when turning, not straight ahead and not brake-induced, ever since I’ve had it. It’s never been diagnosed and has remained present through several recommended attempts to fix, slightly smaller front tire, crank up the preload, replace the shock,  nothing has helped. I am intrigued by your comment about dynamic wheel imbalance disturbance.

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dirtrider
11 minutes ago, Joe Mason said:

I have a 2004 Montauk and have had a shake in front end when turning, not straight ahead and not brake-induced, ever since I’ve had it. It’s never been diagnosed and has remained present through several recommended attempts to fix, slightly smaller front tire, crank up the preload, replace the shock,  nothing has helped. I am intrigued by your comment about dynamic wheel imbalance disturbance.

 

Morning Joe

 

You are tacking your 2004 Montauk  problem on to someone else's hexhead  thread, (different motorcycles).

 

You need to start your own thread about YOUR motorcycle so we don't hijack this thread into a 2004 Montauk thread. (not fair  to the original poster here).

 

If you start your own thread about your problem we will be more than happy to help you.   

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The Rocketman

Joe an invitation has been sent to meet me at www.Chromeheads.org.

 

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