Weight training exercises, barbell curls pointless for a trackie?

Ive started my winter weight training based around olympic squat, deadlift, clean and press with different leg press variations and hyperetensions. during recovery days when my back or legs are still tender is there any point in doing some barbell curls, shrugs and other isolation/bodybuilding type exercises? .

Rather than doing barbell curls I would implement D.B. hammer curls which stress the Biceps Brachii , Brachialis and Brachiordialis these have the most potential for strength and make up the majority of the size of the biceps and also the gripping muscles of the forearm . After all it can't hurt to have strong forearms it gives you a direct connection to the bike .