After the backlash from upgrading an entry-level bike, we decided to reverse engineer the upgrades to see which ones made the biggest difference in speed. We compare the fully upgraded setup, the stock bike, a tire/tube-only upgrade, and a $6,000-plus pro bike on a challenging test loop. The results prove that tyres and inner tubes are the most cost-effective performance upgrade you can make, saving you a whopping 56 seconds on our test loop! | GCN Tech