Am I sinful for shipping non-genuine products on a motorcycle, knowing that my work is limited to shipping only?

If the products are permissible (mubah), then transporting them is permissible, whether they are original or not. However, if the seller deceives customers by selling non-original items as original, then this is forbidden deception, and he must be prohibited from it. If he does not stop and you know that he is deceiving, then it is not permissible for you to transport these goods, as it would be assisting him in something unlawful (haram).