I see this on the street I'll jump and knock the person off of it . The derbi ds50 was worth atleast 3500$ on the high end.. I spent 150$ just for a custom made 22 tooth sprocket.. and like 500$ in machining everything. So many hours of porting the cylinder.. the list of mods is posted on the performance section under the derbi unrestricted thread. Mars, did the custom head for me to run the correct squid band. Here is video of it.. screaming.. It mildly tuned. Wish I would of put a 24mm carb on it with mlm conversion for the 8 petal reed setup.