Head Shake or wobble Q

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mjac

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The bike, an '06 with 10,600 miles.

The new tires took 40 grams (?) of weight to balance.

Mounted and balanced a new set of Avon Storms. The new tires took 40 grams (?) of weight to balance.

I have noticed at low acceleration and low speed <15-20 mph a wobble or shake. This the best I can describe it. I could notice a decreasing wobble up to about 90 MPH and it would go away. Or I could not notice it anymore. Additionally at slow deceleration, 20 mph to almost stopped, I can notice a similar wobble.

Tire pressure was originally set at 40 front and 42 rear (cold), but the front was eventually lowered to 38 psi (cold). This changed nothing.

The new tires where taken back to the mounting shop, on the bike this trip, and removed and re-balanced and put back on the bike. The weight was reduced to 30 grams (?) and repositioned approx 6" from the original location.

I never noticed anything similar to the above while running the former tires though out their life. This condition has only reared its ugly head in the last 150 miles with new tires.

I still have a low speed wobble and am thinking a steering head bearing tightness is in order.

Any thoughts?

 
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I dont have much help for you but I know what your talking about. There are just some innate tendencies on the front end of this bike to be a little quirky. If I let go of the handlebars at about any speed I will get some tremendous headshake, this becomes better and worse depending on which front tire I have mounted. There is also a "clunk" when applying front brakes, and all kinds of conjectures as to why. I dont know, I just keep riding. I've checked torques, bearings etc.. and all are within normal range. This probaly doesnt help much with your front tire wobble problem, sorry!

 
The bike, an '06 with 10,600 miles.The new tires took 40 grams (?) of weight to balance.

Mounted and balanced a new set of Avon Storms. The new tires took 40 grams (?) of weight to balance.

I have noticed at low acceleration and low speed <15-20 mph a wobble or shake. This the best I can describe it. I could notice a decreasing wobble up to about 90 MPH and it would go away. Or I could not notice it anymore. Additionally at slow deceleration, 20 mph to almost stopped, I can notice a similar wobble.

Tire pressure was originally set at 40 front and 42 rear (cold), but the front was eventually lowered to 38 psi (cold). This changed nothing.

The new tires where taken back to the mounting shop, on the bike this trip, and removed and re-balanced and put back on the bike. The weight was reduced to 30 grams (?) and repositioned approx 6" from the original location.

I never noticed anything similar to the above while running the former tires though out their life. This condition has only reared its ugly head in the last 150 miles with new tires.

I still have a low speed wobble and am thinking a steering head bearing tightness is in order.

Any thoughts?
My one experience with Avons (not the new Storms, but the previous cat's-ass Sport-touring Avon) on the FJR tell me that what you describe is part of the deal with this particular combination of bike and tire choice.

They were really nice in the corners and wore well, but had a nervous feel in straight-line travel, as if the front was always wanting to begin a turn that I wasn't necessarily asking it to.

Also, at slow speeds, there was a distinct weave that I chalked up to the rear tread pattern. This became a non-factor after a few hundred miles and the tread wore enough to not carve so much.

I too, experienced handlebar flapping at 30-45 mph speeds any time I let the bars do it. This has not been an issue with the Stock Bridgestone's, Michelin Pilot Roads, or Pirelli Diablo Strata's, so I'm not worried that there is a problem with the bike.

If you remember that the natural position for a motorcycle is on it's side, it's really not that big of a deal, and for all intents and purposes, normal.

Just my thoughts,

Shane

 
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I experienced the same symptoms as you've described with the Avon 45 ('06 w/6800 miles). After multiple mounts, dismounts and rebalancing the problem would not go away. After putting up with this wobble for almost 1000 miles, I finally called Avon.

End result, the tire was replaced and the second tire balanced easier and displayed none of the prior bar shaking. If you are not happy with the tire, return it to the selling dealer and have them take it up with Avon and get the tire replaced.

--G

 
I have had a similar feeling with Pirelli Diablo Stratas. They are very sticky, however at highway speeds in a straight line the bike just feels a little squirrely. As if the rear wheel is not tracking perfectly behind the front. It is very minor and most people would not notice, but I noticed it right away after replacing the stock Bridgestones.

 
perhaps not related to this issue at hand, but i've noticed that quick-turning tires tend to not hold a steady straight line (being somewhat twitchy in the straights) and vice versa. I've attributed it to their quick response to input and needing to personally adjust how heavy handed i might be with my control input.

 
Last edited by a moderator:
The bike, an '06 with 10,600 miles.The new tires took 40 grams (?) of weight to balance.

Mounted and balanced a new set of Avon Storms. The new tires took 40 grams (?) of weight to balance.

I have noticed at low acceleration and low speed <15-20 mph a wobble or shake. This the best I can describe it. I could notice a decreasing wobble up to about 90 MPH and it would go away. Or I could not notice it anymore. Additionally at slow deceleration, 20 mph to almost stopped, I can notice a similar wobble.

Tire pressure was originally set at 40 front and 42 rear (cold), but the front was eventually lowered to 38 psi (cold). This changed nothing.

The new tires where taken back to the mounting shop, on the bike this trip, and removed and re-balanced and put back on the bike. The weight was reduced to 30 grams (?) and repositioned approx 6" from the original location.

I never noticed anything similar to the above while running the former tires though out their life. This condition has only reared its ugly head in the last 150 miles with new tires.

I still have a low speed wobble and am thinking a steering head bearing tightness is in order.

Any thoughts?
I had exactly the same with my Avon Storms.

While i was doing a front fork rebuild I noticed that the tire seemed to be deformed so of to Cycle gear for a new tire (Diablo) now it seems fine even with a storm on the back and a Diablo on the front.

No more Avons for me.

R

 
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