Okay im kind of stumped on this one...

First of all i dont know what an out of balance front tire would feel like... so this could easily be the problem

I have a 2014 Fat Bob... realitively low miles (rolled 18k this weekend)

I rode the bike home to southern california from San francisco friday, with the original front tire. Bike rode great and was stable even well past 100 in a few areas

Got home, and before i rode back up Yesterday i replaced the front tire, and did some additional maintenance. (Critical fasterner check, changed the fork fluid to maxima V-twin oil, brake flush, oil change, etc)

Loaded up and headed back to San Francisco yesterday for work today.... Almost immediately when traffic would allow i noticed a slight wobble around 90mph... And in long sweeping turns.

This bike has never been unstable, and has never even made me second guess anything.

Im wondering if this might be a balance issue? It does seem to be a litttle bit worse on concrete freeways vs blacktop but its there all the time. Seems to come in around 85-90 and was still slightly there even up to 110. Or could it be the bike doesnt like the havier maxima fork oil? I believe its 20wt

ideas? Im thinking about buying some dyna beads and trying that...

thanks

 

Go slower?

I kid.

Nothing says that new front tire, or the static balancing isn't the issue. Avoid the dyna beads; Ride On is what you want. Remove the wheel weights once you go to Ride On, the Ride On will dynamically balance; I won't ever go back to static balancing again.

You changed out the fork fluid; I'd assume you had the fork tubes off the bike to drain the old fork fluid properly? Both tubes were correctly re-filled to the same spec? How's the fork tube protrusion? The tube protrusion on each tube needs to be accurate.

You used heavier 20wt fork fluid; are you running heavier springs? Remember, springs have more control over compression, fork fluid height and weight has more control over rebound damping. Do you have any headshake, the front wanting to over-steer in corners, or any front end harshness over consecutive bumps?

If you've got those fork tubes set up with proper fluid height and protrusion, I'd suspect the new tire or the balancing done on it. You could try the Ride On before you condemn the new tire

 

my fat bob gets a shake at 90mph if I have the hd quick release windshield on, no windshield and its smooth as silk

 

Thanks for the info, ill answer your questions in order

1. yes, the fork tubes were off the bike. the fluid was drained into a measuring container and the exact same amount was put back in. Along with the cleaning of the springs, washer and spacer tube.

2. Tube protrusion was set exactly where it was before i took it apart (measured with a dial caliper and re-set at the same depth) After verifying the tube protrusion was within spec in the manual

3. Stock springs, i just changed the fluid. when i purchased the fluid i didnt even realize it was heavier than the factory HD oil. I just bought the "v-twin oil" i didnt even notice it was 20wt.

4. The ride is significantly stiffer but better than it was before. it was really "floaty". I noticed i cant turn like i used to, meaning i used to "bounce" the bike off a hard lean during a turn, now the bike kind of springs away when i do that

I am thinking about buying whatever beads my local cycle gear carries and trying that out. Or maybe its best to swap the fluid out agian to the stock weight?

 

i do have a windshield, but its not the HD one its a national cycle one

I did change the position of the windshield down lower to the headlights... i wonder if thats it...

I had the windshield on it on the way down on friday and no wobble, but it was in a different position

 

 

You did everything right

The sad HD OEM springs and fluid weight are a big part of that 'bounce' you've felt coming off corners. Now with heavier fluid helping to damp out rebound, she comes back differently.

Personally, I'd pull off the wheel weights and try the Ride On before I did anything else; remove a poor balance job from the mix first, before you go any further.

Take it one step at a time, and you can find these Dyna wobbles

 

Thanks for the video, a weave more describes what i noticed... but laying on the tank did not help at all

 

So i looked at the wheel and there are no wheel weights on it. I called the place that sold it and mounted/balanced the wheel and they told me it is not uncommon for it to not need any weight to balance

I think im going to try a form of beads and go from there