hi my TR77 has the flanged front sprocket and a flat rear 42T am not sure if the front sprocket has a spacer I will have to check but the problem I had with the chain was for some reason jumping has the split link was running over the front sprocket so I turned it on the inside so the split link is on the inside. it runs ok like this but may be. The 11T would. Be. Better question can you get the tab washer on the 11T Orr dose it not have 1