Putting this here cause I think it will get the most exposure so I can get an answer. got a buddy with a 08 Road King. Just put on a set of beach bars. Dont remember the brand just remember they are like 3-4 times heavier than his stock bars. They are extremely comfortable. Bike is fantastic to about 80 then he almost goes into a tank slap situation. Very dangerous and very odd for this bike. Before this bike would peg the speedo with no problem. With that rider the bikes sweet spot was 88 mph. All the way from Arizona to Sturgis this guy would stay at 88 with a big smile on his face. No worries just cruising along. Now.... Not so smiley. What would cause this with a set of heavier bars. He mentioned fall away or drop away or something to that effect, I said check to make sure you got your wheel weights. ANY IDEAS would be helpful. Thanks in advance.

 

i have beach bars and have not experienced straight wobbles just in the corners and new tires and proper suspension pressure fixed that. if they are newer tires he may check into a rebalance of them

 

I agree with the re-balancing the front wheel. Unfortunately, the dealer may say that they are balanced okay as their machine probably doesn't get the spin rate up anywhere near 80 mph. Then when you complain that the problem is still there, they tell you not to ride at 80 mph because that's higher than the speed limit. Might try an independant if you know one that has a balance machine and see what he says.

The only other thing I can think of is, are his hands further apart then they were before. Could be wind resistance hitting his arms. I actually had a windshield cause the issue you refer to. Scared the s**t out of me and I've never had a windshield since.

 

I have beach bars on my 03 RKC and everything is just fine.
If I had that issue the first thing I'd do is put the old bars back on to see if the problem was still there...if it was then that would eliminate the bars from the equation. Then I'd move to the front tire assembly-check front tire pressure, then balance, then I'd check the front calipers to make sure they weren't dragging or sticking. I'd also make sure the bars were seated right in the triple clamp. But wobble at any speed is usually a tire balance issue. Could just be coincidental that the tire reached it's wear point.