If you’re looking to slacken your bike’s geometry a bit, Wolf Tooth Components now offers an adjustable geometry headset cup to do just that. The lower cup effectively extends the head tube which changes the head tube angle of your bike and raises the bottom bracket.
The geometry change makes a mountain bike more stable in descents while improving bottom bracket clearance. The extender can also maintain geometry if you switch a suspension-corrected frame from a suspension fork to a rigid fork. Wolf Tooth has the extenders listed for sale now at $55 and available in multiple colors.