I own a 2004 fxd that my wife is starting to ride and a 2006 fxdci. The fxdci when I am 5th gear at about 45 mph sounds like it is lugging, if I shift in to 6th gear at 50 mph I can't hardly hear it. I brought the bike to the harley dealer and the shop foreman after riding it said that the gear ratio from 4th gear to 5th gear has a wider gear ratio than all the other gears. I have checked the gear ratios and that is wrong. The noise sounds like a real bad heavy pining. Please give some input. Thanks

 

Throw the recommended shifting speeds from the 06 manual out the window. I had the dealer check mine out for the same thing. You're lugging your bike in 5th at 45mph. If you're accelerating at a nice clip, you could even hold 3rd at 45mph. I bumped up my mph shift marks by 10mph from what the manual says for day-to-day riding. The manual is way too conservative, IMO.

Whiff

 

I agree. My Dyna Is happier when I shif at a higher speed. I usually go into sixth at 60 to 65 mph.

 

Ditto!