These are both neat but they both have hub motors, which aren't suitable for offroad use at this point in motor development. I tried to warn Bultaco about this when the Brinco was in development, and the guys at Stealth but they went ahead anyway and either have to compromise on their performance goals and estimates significantly, or build really heavy, unpedalable bikes. I bet both are way more fun than regular mountain bike or dirtbike though!