Generally the Roast is more of a Dirtjump style bike,which would not fit in with a bike like an Evil Imperial or a 24 Letoy IV. Kona's Dirt Jumping bikes seem to do really well with a fork that has 5" of travel. They just feel right with that much travel. With your situation, a Z1 or Dirt Jumper 3 will do wonders.
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Appreciate the old bikes more than the new.