i would not recommend doing bicep curls for motocross.
You should be careful with pull ups so you do not bring your forearms into the exercise.
If you are working in the 10 rep range then you are working on hypertrophy (mass building) and this will hurt you in the future if you are not careful. your routine should have a purpose.
phase 1. muscle adaptation, 10 to 12 exercises, 2 to 3 sets, 15 to 20 reps.
phase 2. strength, 12 rep range, 8 rep range, 3 to 5 rep range. alternating days.
phase 3. power, explosive moves with correct form.
phase 4. muscle endurance, high rep light weight, speed of movement is very important in this phase.
Your legs and core should be your number one concern then upper body.
this gets a little complex buy with some research and information you will begin to understand.
Alan