Milwaukee 8 vs Twin CamB balancer designs
 

* The Twin CamB uses two weights on the flywheel and a chain between the balancers.
* The Milwaukee 8 uses a gear driven counter balance off of the crankshaft.

​​​​​What are the Pros and Cons of each design?
What design is more efficient? Longevity?
I have been told the Twin Cam balancer design can eliminate more vibration.

You also have not considered that the touring M8 has a single counter balance shaft whereas the Softails powered by an M8 use two counterbalance shafts.

Chain can be potentially quieter. Gears offer greater longevity and less maintenance.

What I was kind of surprised about with the M8 is the use of a chain on the cam shaft.

As a point of reference, Evo's didn't use counterbalance shafts and the cam shaft was gear driven. Sportsters don't use counter balance shafts and have four gear driven cam shafts.