Ive been throught this before with this problem but someone might have another idea to help me. I have a 40t rear sprocket on a carrier that clamps to the rear hub, first I had the problem of it slipping but thats fixed (touch wood) now the problem is the sprocket isnt aligned the chain goes tight loose ect ect. The carrier must be drilled a little off centre, I cant file it out it will be to big for the hub can anyone think of a idea to get it true thanks mick29