Originally Posted by
12boy
The cheapy cranks are lighter than the ones with replaceable chain rings. They have two disadvantages...when the teeth are worn they must be thrown away and you are stuck with only one size choice. I have used both on my Brompton, though, and the cheapy one is my current choice, partially to offset the weight of the IGH hub and my leather saddle. In over 5000 miles I have not succeeded in either wearing it out or breaking it, although I am fairly light and don't stand up and mash the gears a lot.
My 2013 has the spider cranks; pretty sure it's lighter than the old style. Dura Ace ring and protector removed.
I think the bottom bracket is different for each style as well.