I save my old OEM chain and sprocket- to use another day-maybe a real long trip-I put it back on- I have a chain tool that needs a part. I let shop put new chain on -I want to try out those two extra teeth-may slow up the bike a little so I don't stall it-happened twice on me-once in second gear and once in first. I think lowering the tranny and use the higher gears will cut some wear on 1, 2. A test was done on 530 and 520-gained 1.5Hp. and maybe 2 pounds light-not much. otstir: