Nic's (right) hair is almost always straight, while Tristan's (left) is always curly!

Tristan (left) has a different smile than Nic (right). Nic's adult teeth came in before Tristan's, so they are straighter.

Now, their helmets have new designs on them, but usually, Nic (right) wears a light or white helmet, and Tristan (left) wears a dark helmet.