This in-depth post with comparative chart and video reviews provides all the info you need to choose between the Garmin Edge 530 vs 830.
Garmin Edge 530 vs. 830: Which One Should You Buy?
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Edge 530 Review VS Edge 830 - which should you buy?
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Garmin Edge 530 vs. 830: Which One Should You Buy?
Garmin Edge 530 vs. 830: Which One Should You Buy?
Performance GPS cycling computer with mapping and touchscreen Dynamic performance monitoring provides insights on your VO2 max, recovery, training
Garmin Edge 530, Performance GPS Cycling/Bike Computer with Mapping, Dynamic Performance Monitoring and Popularity Routing (Renewed)
Edge 530 Review VS Edge 830 - which should you buy?