When sourcing budget-friendly bicycles, prioritize ISO 4210 compliance, which covers safety requirements for city, trekking, and mountain bikes. Ensure the frame material (typically Hi-Ten steel or 6061 Aluminum) has clean, consistent welds. Request load-bearing test reports to confirm the bike can handle at least 100kg to 120kg. For 'cheap' models, the most common failure points are the bottom bracket and braking system, so specify branded entry-level components like Shimano TY series or reputable domestic equivalents to ensure longevity.