I have 3 front sprockets for a 636.
1 13 tooth new 2 used. 14 &15 tooth
1 new split rear 53 tooth
1 used split rear 52 tooth
1 used chain with less than 3 races on it. I think it's a DID. I know it's best to buy all this gearing new but this stuff is in really good shape. Text me @ (270)994-1371 for more pix.