This is our Standard Truck It has cupped seats, and useing larger 3/8 bearings in
a cupped seat casting gives smoother operation. Machined spindle.
Clean cut threads for easy install. Large metal sheave on solid ss pin.
Standard truck tops have loose bearings.
This truck has a cupped race so bearings sit in and make more contact.
Some companies use smaller diameter bearings on a flat, rough unfinished surface,
typically they seize up after a while as bearings grind into seat and plastic holder
makes contact with base and becomes a friction break shown here.