On the minipocketrockets website their is The X18-R Nitro Super Bike". It sais the "R" stands for race edition and seems to be the same as the X18 but revised and better. minipocketrockets is the only website that i've seen that has them so i'm a little curious if this is better than the X18 or just a cheaper made model with worse parts. The website is selling it for $599 plus $57.82 shipping and handling. Im wondering how this bike compares to the regular X18. Any opinions or thoughts?