Are cheap Amazon spin bikes durable?

It's mixed. High-trust community voices in r/cycling caution that some Amazon-only brands use weak pedals and crankarms even when the flywheel and belt are smooth, and warned about noise and build quality on Amazon-exclusive brands. Verified-purchase reviewers, however, report multi-year reliability on YOSUDA, Merach and DMASUN units, so component upgrades (especially pedals) are a common recommendation.