Cook the rice noodles according to the packet instructions. Drain, then refresh under cold running water.
Mix together all the other ingredients, except the pancakes or ricepaper wrappers, in a large bowl. Add the noodles and toss to mix. Cover and set aside for 10 minutes to allow the flavours to develop, then transfer to a serving dish.
To serve, let people take a pancake or ricepaper wrapper, top with some of the crab and noodle mixture, roll up and enjoy.