SG Auto Change Base
Blade Base: SG Auto Change Base
Can only be used with SG (Auto Change Version) core part.
Technically the heaviest Blade Base, though this serves little practical use given the design, gimmick, and inability to use a Heavy Metal Core.
Tip-change-on-hit gimmick - when bulky parts with screw/bolt details are hit, sharp tip retracts leaving a hole flat tip.
In left spin, the opposite occurs, with the sudden protrusion of the tip making the Beyblade hop when hit, usually resulting in SG Auto Change Base exiting the stadium.
In either direction the Base can be started in the post-hit position to stay in that mode for the duration of the battle.
Huge, relatively light for its size, recoil-laden, either aggressive with poor grip or largely immobile with little defense, and with a poorly-executed gimmick - a useless part.
Comes with the heaviest base clips of any Beyblade (~0.47g each) though SG Metal Sharp Base's are almost identical in weight so crossover is possible. Due to their large size and the fact they protrude greatly on practically every Blade Base, this serves no practical purpose.