Use a group action.
From sprite kit programming guide:
A group action is a collection of actions that all start executing as soon as the group is executed. You use groups when you want actions to be synchronized
SKSpriteNode *wheel = (SKSpriteNode*)[self childNodeWithName:@"wheel"];
CGFloat circumference = wheel.size.height * M_PI;
SKAction *oneRevolution = [SKAction rotateByAngle:-M_PI*2 duration:2.0];
SKAction *moveRight = [SKAction moveByX:circumference y:0 duration:2.0];
SKAction *group = [SKAction group:@[oneRevolution, moveRight]];
[wheel runAction:group];