A 415 Trike/Industrial chain still has the same 415 chain dimensions of the stock china girl chain- but smaller plates vertically- so it's about half the weight and it rolls much easier- if you ride street and fairly clean I reccommend and always use- less than $15 shipped still I think- one drawback is that it has usually just about as many links as a standard buiild takes- so if your chain is n the longish side, you may need two. 110 links I think it has.
http://www.piratecycles1.com/kmcin415ch.html
here's one at Pirates or search elsewhere
Some kits come with a 1/8" pitch 410- same size as normal cruiser bike chain -which works for some i guess- I tried one once and had some problems-allignment must be perfect- and harder with no tensioner as I like (and you have to have a compatible front motor sprocket)
so I still like the extra width of the 415- no fuss no muss- rolls MUCH better and much lighter than kit chain-and probably no more weight than the 410-
no failures yet on two builds after about 2 years.
Just for information's sake- I think the regular 415 kit chain came along AFTER the general use of a 410 on motorized bikes- and some people stayed with 410 to save weight I guess- the 415 Trike then splits the difference between the two