The RNC Legend Cranks are honestly just crazy. If you're a weight weenie or just like expensive things then these cranks are right up your alley. Being the lightest BMX cranks ever made is a bold thing to do Cotton. The man over at RNC used some crazy high tech metals and sorcery to make these possible, so with that said here is an excerpt from his site explaining some stuff about the metal properties that I do not understand.
***Also take note these only work with RNC 24mm bottom brackets and sprockets. Apparently every other BMX brand does not use an actual 24mm sizing. However a mid bottom bracket is included, and the proprietary sprocket can be purchased here. ***
"The lightest and most high tech BMX cranks ever made.
Arms are from maraging steel the strongest aerospace high strength steel in existance and heat treated to a 300,000 tensile strength including the welds.
24mm 80 tooth titanium spindle made from a BETA C grade 19 titanium that’s heat treated to an unbelievable 220,000 tensile strength. This titanium has the highest strength of any titanium and also has the highest strength to weight ratio of any metal in existence.
Cranksets come with two arms a Beta titanium spindle and titanium flush mount bolts.
Spline drive for lhd and rhd compatibility.
Crank weight for 165mm with 5.625 length spindle is 12.4 ounces or 352 grams.
Lifetime warranty against manufacturers defects.
100% MADE IN THE USA"