using double flanged wheels is a result of poor carriage design. since thier carriage and drive systems can rack they need to build complex scro drives that most well engineered systems do not need until the system is over 25 feet. the double flagened wheel jsust help to reduce carriages caoming oofff track bexcaiue of poor desin. thwey cover by saying the systmn ahs syro but it pooor engineer that makes it reqwue these wheelas and scro. he sycro is so poor they do not offer on heavy and long carriages! what does that say?