Made from a proprietary 7000 series aluminum with a 103,000 tensile strength. 30% stronger and harder than 7075-T651 aluminum and a higher strength to weight ratio than 6al-4v titanium. 24mm 80 tooth titanium spindle made from a BETA grade 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. Cranks come with 2 Aluminum arms a Ti spindle and Ti flush mount bolts. Titanium sprocket adapters are available to run Profile sprockets. (For mid bottom bracket users this crankset requires our 24mm mid bearings. Mid bottom brackets advertised from other manufacturers as 24mm are not 24mm and will not fit they are smaller. ) Crank weight for 170mm with 5.625 length spindle is 19.8 ounces or 560 grams.