Seismic claims the Tantrums to be the lightest and most functional freeride wheels available. When you consider the lightweight Energy Conversion hub surrounded by Seismic’s Elixir freeride urethane, it’s easy to believe. Elixir urethane is well known for its predictability and smooth transition into slides, while the EC hub limits the effort needed to push into slides while also cutting down the overall weight of the wheel.