Looked all over internet for 84 tooth sprocket no luck.I have a 3 wheel schwinn with predator 212 with a 60 sprocket its very fast.I live in trailer park in the foothills with dirt and bumpy roads its hard to get up on some of these roads so more torq is needed less speed no problem Thanks for any help Im also a noob to 3 wheel motorized bikrs and forums.Thanks