Is it legal to sell a old motorcycle for one dollar?

In general yes, a motorcycle can legally be sold for one dollar. The legality of any sale, including the sale of a motorcycle, is determined by the contract law of the jurisdiction in which it is made. Contract law establishes the legal framework for sales and transfers of property. In most jurisdictions, as long as the seller and buyer agree to the terms of the sale, it is considered legally binding, regardless of the sale price.