I have tryed to find a bigger sproket it has 40 teeth 6 bolt in the center if anyone can help or just put me out of my misery, lol, But no, i have had this Hi-bird komoto whatever you want to call it and never had any problems with it and to be blunt i ripped the **** out of this toy and it is still going I had put it together my self with a lot of lockwashers but after all the crap i have put if throught it's still going strong! thanks for anyone's help I just hope you can.!