[s1artibartfast]

>Are some portion of sold pelotons "used", without disclosing this to customers?

Im not sure I follow what you mean by "used" what disclosure you are referring to.

>What do they do with returned equipment?

Probably either scrap them or refurbish re-sell. This would be similar to when car manufacturers issue a recall with a buyback option.

[cwkoss]

Are refurbished used pelatons a separate SKU, or do customers buying new pelatons get refurbished ones without realizing it?

[s1artibartfast]

No clue, I dont work for Peloton. for all I know they end up in a garbage dump.