Sonic Headcanon: There are three defined styles of Extreme Gear: Alpine Gear, BMX Gear and All Around Gear.
Alpine Gear are the types that show up in the first Riders. They’re incredibly fast, lightweight and able handle different typings without Gear Part accommodations. On the flip side, it struggles when going off-road, is not able to accommodate Gear Parts of any kind with extra features having to be built directly into the gear and runs entirely on an air compressor based engine system, so when your air tank runs out, you’re SOL until you can either catch some air or reach a refill station.
BMX Gear are the types that show up in Zero Gravity. They’re a lot heftier, a lot more durable and versatile when it comes to taking them off-road and have the greatest Gear Part accommodations of all gear types. There’s also more types of gear, based on different styles of extreme sports, available to accommodate different styles, such as Wheels for power type racers and Air Riders and Yachts for flight type racers. In order to power them, however, they completely eschew air compressor based engines in favor of more conventional electric engines. This allows them to run for a lot longer and charge a lot easier while being unable to achieve the same speeds as either Alpine or All Around type gears. They’re also the only gears that can stand up to the extensive usage of Gravity Control that Zero Gravity had.
All Around Gears are the types that show up in Free Riders. They’re the middle ground between Alpine and BMX. More durable and able to support some gear parts, but still relatively lightweight able to reach decent speeds. They use a smaller scale air compressor boost engine, but also employ an electric sub-engine that keeps the gear running when the tank is empty, but at a severely reduced rate. These gears would be the best gears for day-to-day use.
Rather than remaking the gears each time, Team Sonic and the Babylon Rouge instead use different base gears for each iteration of their signature gears. That means that Sonic still has the Alpine type Blue Star II somewhere and Tails, Wave, Storm and Knuckles still have their BMX hybrid board/air ride and board/bike gears somewhere.