Drive shaft assemblies are very heavy, and of questionable value on a lightweight RE. O-ring type chains are a quick improvement over the factory setup, but they do not address the primary limitation of chains--frequent maintenance and limited durability. I have yet to hear anyone mention belt drives--they are both stronger and quieter than chains and require much less maintenance. After having belts on my last two bikes (Harley-Davidsons), I would not want anything else.I was also surprised to learn that belt drives are not offered as an upgrade by CMW, or even mentioned in this community forum. A belt drive would be an immeasurable improvement to anyone's RE, and I am already scheming on how to have one adapted to fit my 2009 UCE.