I was running poly bushings and torqued the living **** out of them. Started off with 30lbs, then stepped up to 45lbs in 5lbs increments. The bars were rock solid.

 

On my 05 Springer I have 16" chubbies with 4" risers. My front tire is a 21 and my rear is a 16, just to answer the issues about maybe lower in the back thing. I've had them for around 9 years and have put somewhere close to 80k miles riding with this setup. I've ridden in town, on twisty roads and at highway speeds. Around here, I normally cruise around 70 but depending on where I was riding I have maintained speeds of 80+ for long distances and the only vibration I had was at speeds of around 60 and that was because my front tire was out of balance. After my Indy took care of the balance issue, I never had any more vibration/wobbles.

 

If you install an ape, its recommendable install a new riser bushings in the tree. But install heavy duty specification riser bushings.

 

If your bike is lowered in the rear like mine, and stock height up front, you could throw in a 2" progressive drop kit and see how that works. If I had the stock FX forks on mine, I would have tried that...

 

By lowering the front you're actually changing the trail which leads to instability. Lowering the rear alone doesn't change this geometry since the trail calculations are taken from the front end.

Have you checked the fluid amounts in the forks? A difference can cause shaking or wobbling also. I had a wobble on my train when I went to 14's but just tightening up the neck bearing a little took care of it right away.

 

I have 16" apes and rode at 160 kph/100 mph (legally) and didn't feel any sort of wobble.

What pisses me off though is when I have a real wobble and it is dismissed because of the apes.

 

went to check out a Break out ...not sure if I could let the train go...Now searching for maybe 12" bars to swap on..