In the most simplistic terms, Chris bough a bike and agreed to pay the full amount by the date recorded in the contract.
Chris has not paid that amount.
That seems to be the reality of it. It's a transaction gone bad. HP needs to stop posting and start acting. I haven't read every post in detail so I'm not sure if she has already filed in small claims or waiting but that is likely her best option. As stated earlier, followed by a garnished wages.
To be fair, a 30year old with no job and sleeping on any available sofa likely won't care about the judgement against him thus you'll need to find a way to reposses the property and take him to small claims for usage/damages.