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Discussion Starter #1
I have Conti Road Attacks on my RT. Verifed 42 psi in the front and rear tire. I am getting some nasty head shake at 50mph. Nothing really below or about but when I hit 50 and let go of a bars.....Drama. Any ideas? Could this be a balance issue?
 

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Are these brand new tires or have you had them for a while? If you have had them for a while, did this shaking just start or have they always done it? If it does it a one speed, it probably is a balance issue.
 

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flienlow said:
I have Conti Road Attacks on my RT. Verifed 42 psi in the front and rear tire. I am getting some nasty head shake at 50mph. Nothing really below or about but when I hit 50 and let go of a bars.....Drama. Any ideas? Could this be a balance issue?
Hi i have the same issue with my suzuki c90 i sure its the front tire there is some cupping when i let go of the bars it shakes when im holding on its ok check the front tire..
 

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Try 36 psi in front. I believe that is what the factory recommends. Other things besides tires cause head shake and RT's don't ususally have this issue. A very stable bike. Something's wrong somewhere.
 

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I haven't heard anyone in my club ever mention this problem with the RT. I agree that the pressure sounds too high, I think the manual has 36 for two up riding. I can go down and check if you don't have a manual available.

If they have just been installed, I'd check the balance again if it goes away at 55. Also check to make sure the tire has been installed in the directionally correct manner.

Let us know how it turns out. Like I said, I've had that situation with my Harley, but never heard an RT doing it.
 

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On the RT, it's highly unlikely head shake would be caused by tire pressure. If the tire is good and the wheel is true, the only felt change from low to high pressure is how slow or light the front end feels and the amount of road feel [ie, ride is soft or harsh] transmitted through the bike to the rider.

More likely is either a worn tire, really bad balance or a wheel with a run-out problem. Head shake on a mototcycle is also not necessarily limited to the front wheel. It could be caused by a run-out problem at the rear.

In addition to that, from your description, it honestly sounds like balance more than head shake.

Questions:

1) You say it happens at 50. Can you ride out of it at 65 or higher?
2) How old is the tire?
3) Have you hit anything in the road recently?
4) How long has this been happening?
5) Do you have aftermarket TPMS? If so, was the wheel balanced with the sensors on the wheels?

Check wheel true - front and rear. I'm going to presume you don't have a run-out gauge. Bike on centerstand, bags off. Stabalize something [you can use a Sharpie marker or a pen] so it's almost touching [the closer the better] the rim on the rear wheel - slowly turn the wheel all the way around and see if the gap gets smaller between the marker or pen or whatever you use anywhere on the side of the rim. Minute change is ok but if you do fine minute change, you should switch to the other side and measure that as well to make sure one side doesn't have more run-out than the other. That can be caused by hitting something or just a bad rim. Repeat at the front. If both front and rear are true, look to a bad tire.

This is a run-out gauge:



One last note - the primary reason I suspect it's not really "head shake" is because head shake is caused by an imbalance in load bearing and flex in the front end of a conventional front end. On the RT, the telelever is the stressed member, not conventional forks, and that stress is on the engine/frame, not the triple clamp. With a single strut/spring assembly between the telelever and the upper clamp, true head shake is almost impossible.
 

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Discussion Starter #7
Questions:
1) You say it happens at 50. Can you ride out of it at 65 or higher? - YES
2) How old is the tire? Used bike, dont really know.Email sent to seller.
3) Have you hit anything in the road recently? - NO
4) How long has this been happening? - Since was shipped to me.
5) Do you have aftermarket TPMS? If so, was the wheel balanced with the sensors on the wheels? - NO

I bought this bike off C/L in AZ. This may be crazy but I never saw it. I had a friend go look at it for me. BTW I am satisfied with my Results/Risk, but would proabably not do it again. The reason I did it was because I could not find a used RT like this anywhere with in 1000miles. The Seller is a standup guy, and I did purchase a used motorcycle.
 

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Ok great. Doesn't sound like a bad C/L experience.

My money is there's nothing really wrong with the bike in this issue. I'd gamble it's either tires or balance.

Consider getting to a BMW dealer [other dealerships generally don't have the adapter for BMW wheels] and have the tires balanced if they otherwise look good. If there's any question about them, I'd replace them. Later, when you learn more about your bike, you'll likely be doing the changes and balances yourself. Not hard, just time.

Most of us seem to riding Michelin PR2 or PR3s. I ride PR3s and strongly recommend them.

Welcome to the BMW fold...
 

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I've noticed head shake on numerous bikes, usually on decell. It will shake and then fade away. My LT will do it at a lower speed.
New tires seem to be the cure, until they wore to the point of needing replacement I kept my hands on the bars.
 

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Discussion Starter #10
-you'll likely be doing the changes and balances yourself. Not hard, just time.

How can I do this myself?
 

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Sorry, that's far too much typing for me. I'm currently typing with a cast on my right hand/wrist.

You'll need tools you obviously don't have and learn how to use them with some minor help.

Get dealer help for now and look into it later.
 

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Discussion Starter #12
New2rt said:
I've noticed head shake on numerous bikes, usually on decell. It will shake and then fade away. My LT will do it at a lower speed.
New tires seem to be the cure, until they wore to the point of needing replacement I kept my hands on the bars.

Mine is through the transition either way. if I let go it will tank slap (not just a wobble.) Above or below 50mph -Smooth as butter.
 

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flienlow said:
I have Conti Road Attacks on my RT. Verifed 42 psi in the front and rear tire. I am getting some nasty head shake at 50mph. Nothing really below or about but when I hit 50 and let go of a bars.....Drama. Any ideas? Could this be a balance issue?
On several occasions, I have read on the Web people mentioning some shimmy of the front Conti Road Attack. This could be related.
 

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One little known cause for head wobble is a stretched bead. This happens when the tire is pulled on too hard during mounting and one of the beads is literally stretched and becomes slightly longer than the other. There is no easy way to confirm a stretched bead that I am aware of. I found this out when I stretched one of my own. Other common possible causes are imbalance and tread wear pattern on either tire.
 

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Hammam said:
On several occasions, I have read on the Web people mentioning some shimmy of the front Conti Road Attack. This could be related.
On post telelever BMW RTs? I've never heard of it on a newer [aka, telelever] RT. If you could possibly point me in the direction where I could read about this I'd certainly appreciate it.

Thanks in advance.
 

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steveaikens said:
On post telelever BMW RTs? I've never heard of it on a newer [aka, telelever] RT. If you could possibly point me in the direction where I could read about this I'd certainly appreciate it.

Thanks in advance.
Sorry, I was distracted. It was the Conti Trail Attack, not Road Attack, and on a GS, not an RT. I have yet to get used to the fact that I traded my GS for an RT very recently.
 

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If the bike was shipped to you with the wrong tyre pressure, is it then also likely that the front wheel isnt balanced correctly?
And its a GS, not an RT? Dude- you need more coffee! LOL

Spoked or cast wheels? GS or GSA (determines the likelyhood that its been bounced around off-road...)?

Check for wheel balance, correctly seated tyre (beading around the rim even), play in wheel bearings and telelever front swivel (by fork brace). Visually inspect the tyre for deformations/bulges- I managed to rip the banding out of a Metzeler once experimenting with ABS-stops!!!
 

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I can tell you I had the same problem with a 2009 LT. When I looked closely, I noticed the front tire had some cupping that had developed. I replaced the tire and all of this went away. After that, I was very careful to be sure I kept 40-42 pounds of air in front and rear, as I think running too low a tire pressure may have caused this cupping.
 

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flienlow What the deal on this now? Is it solved and what was done to solve it.
 
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