<https://secure.gravatar.com/avatar/a2f64f7d6c4fe40d9d6c13b510278337?s=96&amp;d=mm&amp;r=g>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.declinemagazine.com/mtb-parts/when-to-replace-mountain-bike-tires/>