The build sheet:

Specifications For Black Briggs Bobber
Frame—————————Probably nos aftermarket hardtail from the 60s
Wheelbase———————58 in.
Rims—————————–18 x 2.15
Tires—————————–18 x 4
Hubs—————————–Honda 350
Brakes————————–Drum
Swept Area——————–56.5 sq. in.
Brakes Loaded—————-8.8 lbs. per sq. in.
Curb Weight——————-300 lbs. / 200 lb. rider – 500lbs.
Fork—————————–Homemade
Rake—————————-25 degrees
Trail—————————–3 in.
Suspension——————–Leaf spring over leading rocker
Floorboards——————-24 in. Wide and 8 in. clearance
Lean—————————-35 degrees
Ground Clearance———–6 in.
Axle to Ground—————13 in.
Crankshaft to Ground——-11.75 in.
Handlebars——————–Lowrise buckhorns 31 in. wide with 5 in. rise on 3.5 in. dogbone risers
Grips—————————Anderson style
Engine————————-V twin ohv Briggs and Stratton
Displacement—————–34.75 cu. in. / 570 cu. cent.
Bore—————————-2.83
Stroke————————–2.76
HP——————————18 @ 3600 rpm
Torque————————-30 ft. lbs. @ 2400 rpm
Exhaust————————two into one header 1.75 in. auto
Drive Train——————–comet ind torque converter
Drive Clutch——————-44 c magnum
TQ Overall Ratio————-2.43 to 1
Final Drive———————428 chain sprockets/ 15t into 60t for 4 to 1 ratio
Speed————————–70 mph @ 3600 rpm
Frame Geometry————-Cloned from Indian 101 Scout
Steering Geometry———–Cloned from Indian 101 Scout