Yhea RC Component are a special bolt pattern. Sprocket Specialist, yhea they ae so helpful!! they only do Alum and Ti-coated Alum, thus is why I will most likely have to make some special. I have to admit that the Ti-cocated alum from sprocket S is holding up very well (onece you get them), it is at least equal to reqular steel. Sure woud lke to get some Ti-Molly sprockets made.