I have a 05 Fat Boy and it feels like it is geared for 65mph max for cruising. If I'm on the freeway (not very often) the bikes RPM's sound / feel like 65mph is about the max, after 70mph it seems like the engine is turning too fast.

Does anyone else feel this way?

What is the best way to change the final gear ratio to bring down the RPM's?

 

I have an 05 "Fat Boy" as well -- driving around town was fine but on the freeway at speeds around 70mph the engine was working cranking higher up in the RPM scale than I would have expected and on "B" motors anything over 3000RPMs can be felt. I solved the problem with a new Baker 6 speed which keeps RPMs below 3,000 at 75MPH and improved dead stop starts and cruzing - I sure wish I had done this before even considering chrome - I also found shitfing far easier and quiter along wtih much less noise. Good luck! ...

 

Randall has the right aproach on this one with the 6 speed. You can also change the rear sprocket size, but that would throw off your speedo. There's the possibility of a change to the primary gearing that would not throw off your speedo, however if you gain on the top, you loose on the bottom this way. Pick up a copy of the Sept. hot bikes magazine and on page 42, it will give you a good idea of what this is about

 

Hey kwb

I know the motor feels like it is over reving but actually at 80 miles an hour the motor is turning about three grand. Redline is about six grand.

The vibration is something us softail owners have to deal with unless we go with a six speed. The bike is actually geared about the same as the cars we drive if we drive without overdrive. The six speed tranny would give you that overdrive and lower the rpms. You will not hurt motor staying with the five speed though.

David

 

Randy how have you got youre motor set up? Are you still running "88"ci. or are you pushing a "95" incher if you are running "88" how does it pull in 6th. I had planed on going "95 " over the winter and then doing the 6 speed next year but if I can pull 6th. with no problem's with my "88" stage one then I might just have swap those two around. Thank's for any help.

 

Hey JB, I had the jugs bored to 95" along with CAMs and a new Ignition. The dyno shows about 100 ft lbs of torque from about 2,000 rpms to 4,000+ and HP low 90s. I am not sure I would have gone with a 6 speed with out increasing the cubes as you do need the extra power when cruzing from about 65mph on in sixth. I as many looked into changing sprockets but found too many trade-offs - as for the speedo with the new transmission it was way off so I installed an electronic speedometer adjuster and using a dyno set made the adjustments. I want to do some long distance cruizing and there was no way I would do this or should I say stand the vibrations from pushing the motor over 3,000rpms even thought its not a problem. I also noticed a big improvement in fuel economy and the motor runs much cooler now at highway speeds - living in FL where its 97+ some days it sure helps. Good luck ...

 

Thanks for the info Randy I guess I will be going with the 95in. first.