High speed wobble???

[Scooter33]

Ok back from the shop. Dude said fall a way is good. The back tire has a slight ridge on the left side??? When going straight there is no wobble. If it ever stops raining I will check it on a curve. If it still wobbles I am going to recheck the fall away and try to contact Avon.

 

[scgorazd]

Have the same problem on my 09 K9. I looked into this extensively. Checked my fall away, neck bearings (repacked), wheel bearings, wheel alignment (rear). Mine would occur around 90-100 MPH. I even took it to Gateway Big Dog here in STL. One of the guys (Tim) took it for a spin and said he got it up to 120 with no problems. I guess it is more a design flaw than anything. I've since had it up to 120 and have more of a problem hanging on then anything. I honestly believe it has to do with the difference in tire size between the front and rear, not really noticeable when going straight, but as soon as you start to turn thats what causes the wobble. If its not doing it when going straight then thats likely the issue. Happy to ride 120 with you anytime you dare, if you can keep up that is

ALWAYS check the air pressure befor riding. If you don't have time to check the pressure, you don't have time to ride. (IMHO)

 

[flcmcya]

Air pressure got me on my Bulldog! :bang:

 

[Th3InfamousI]

I get a bounce (going straight or cornering) between 68-72 MPH that is annoying the hell out of me. The tire is new with new wheel bearings.

I took the rim to the shop who mounted the tire and threw wheel weights. Originally it worse and it bounced between 65-75mph, I figured it was out of balance at that speed? I put in Dyna Beads and reduced the zone in which it bounces now 68-72. Although thats typically a decent cruising speed and although you don't feel it through the handlebars I can see the forks hopping up and down.

Any one have any ideas? I know some have added more beads? I just don't know if more or less is the answer?

 

[Jwooky]

Not a design flaw, mine is rock solid.

I had a belt separation in the rear (yes rear) cause a dramatic wobble. I would remove and try and balance tire/wheels.

 

[jon57]

had that on a Harley dealer said it was fork oil they changed the oil fixed it

 

[woodbutcher]

originally, the '07 had 30wt. oil in the forks. when i changed the bushings, the only thing i could find at the time was 20wt. this made the front end softer and i felt the bumps alot more. next time i rebuild, will find 30wt before i start the job. not happy with the 20. haven't noticed wheel wobble though.

 

[jon57]

they didn't change the oil wt. been in for a time just drained and new oil

 

[LA_Dog]

Yeh was going to say fall-away as well but that would also cause wobble in the straights, plus I see you've checked it.

What type of tires you running F/R? Is there a possibility you're mixing a bias ply rear with a radial front (or vice versa)? It's probably not the case, but wanted to mention it- I have seen similar to what you're describing occur- the tires will bite / step out differently due to their differing construction and can cause everything from wobble to wash-out. low tire pressure could exaggerate the effect.

Anyway, hope you get to the bottom of it as I'm sure it is rather unsettling!

 

[TapioK]

I sometimes have the same thing as Infamous (Hi). Then sometimes bike is rock solid. I've been thinking maybe the beads don't spread correctly everytime? Then again Dog is temperamental and needs motivation. Running after BBChopper, Raywood, Infamous... and their beer and Jim Beam she is rock solid at 125. Figure that. My dog doesn't like sidewind too much either.

 

[San Diego Dog]

Replace the bearings on the neck (triple clamp). I have the same bike but an '08. I have already replaced them just do to wear. There is a lot of strain on those bearings. And if no maintenance is done i.e. re-pack with grease, check for wear, etc. These things are going to happen.

 

[Air Force 1]

Check fork bearings. I had the same problem. Replaced them and no more wobble.

 

[ground pounder]

My 2009 K-9 had the front fork wobble at 70 t0 80 MPH one day and was so bad that if I was not an expirienced rider I would have been road pizza. Turned out that there was only about 2 ounces of oil in the front forks from the factory. Put in the right oil and amount and have had no more problems. Knock on wood!!! I also added an old school tweek bar to the font forks.

 

[Sven]

Had a "slight" shake at 85+... went away after putting new tires on !... replaced both front and rear...

Well, that answers that.

Not a design flaw, mine is rock solid.

And that answers that.

Rear tire new last year only 2k miles. The front I don't know but tread depth looks fine.

Oh boy does that answer that.

1. I walked out the shoe store with a brand spanking new... Man, I sure put on a lot of miles, I need to go back to the store. Oh, no clerk, I only want one new shoe, the other still has threads left on it.

2. I roll the bike out the dealer floor. Oh look! Both wheels move at the same miles together, the step in the front tire I can't see, oh well, I just need one sneaker anyway too. Might as well buy one each.

3. I better call the tire manu and shoe manu. My gate is all wobbly, I couldn't match your 3 year old model shoe against the new shoe design and now I turn a corner and almost fell down and I can't get up!

4. I got this huge click in my ear when I said the bike wobbles with one new and one old tire. It's your design flaw. Oh wait, Jwooky and the manu of bigdog wouldn't put out a wobbbler, guess it's back to the tire.

5. I looked at scuba filling the air in both air tanks and he only fills one to go diving. See that tire manu???

6. I better rub both hands together and see what the hell this guy is saying? Oh, one hand stayed cold. I just need one glove for the winter. How is my wobble theory going?

7 come 11 I'll take the bet = Front Tire Where is the common sense one tire only?

Signed,

NOLTT

 

[pauly]

Well, that answers that.



And that answers that.

Oh boy does that answer that.

1. I walked out the shoe store with a brand spanking new... Man, I sure put on a lot of miles, I need to go back to the store. Oh, no clerk, I only want one new shoe, the other still has threads left on it.

2. I roll the bike out the dealer floor. Oh look! Both wheels move at the same miles together, the step in the front tire I can't see, oh well, I just need one sneaker anyway too. Might as well buy one each.

3. I better call the tire manu and shoe manu. My gate is all wobbly, I couldn't match your 3 year old model shoe against the new shoe design and now I turn a corner and almost fell down and I can't get up!

4. I got this huge click in my ear when I said the bike wobbles with one new and one old tire. It's your design flaw. Oh wait, Jwooky and the manu of bigdog wouldn't put out a wobbbler, guess it's back to the tire.

5. I looked at scuba filling the air in both air tanks and he only fills one to go diving. See that tire manu???

6. I better rub both hands together and see what the hell this guy is saying? Oh, one hand stayed cold. I just need one glove for the winter. How is my wobble theory going?

7 come 11 I'll take the bet = Front Tire Where is the common sense one tire only?

Signed,

NOLTT

One front tyre will last two rear tyres and it is common practice not to change both tyres every time but every second time!
Half worn front tyre combination with new rear tyre will not cause speed wobble in my opinion.

If we were talking two front's and two rear's than I would certainly change
the pair not just one tyre and again front and rear independently.

What's others opinion on this?

Paul.

 

[Redog76]

Totally agree Paul. One front to 2 backs. It is basically opposite of brake pads. 2 front sets to 1 rear set. This is just a good rule of thumb though.

 

[Scooter33]

We think the issue was the extra weight of the bad on the back and the shocks were adjusted stiff like a hard tail. The road conditions and high speed didnt help either. The rest of the rear suspension checked out fine.

 

[pauly]

We think the issue was the extra weight of the bad on the back and the shocks were adjusted stiff like a hard tail. The road conditions and high speed didnt help either. The rest of the rear suspension checked out fine.

Thanks for the follow up! :up:

Paul.