I recomend finding the magic gearing. Break you chain and put on the iddle cog and over the rear sprockets and see which cog gives good tension. If no do then changin the front or rear cog by 1 tooth will change the chain length needed by 1/4". Not intuitive but it does work. I have done this on my Orange Evo2 and it performs flawlessly without a tenioner now. With a tensioner the chain tension was never right for long even with the black Spire BB mounted one. A singulator type tensioner ust never worked well. All I had to do was move from a 32T to a 34T chain ring and that added 1/2" to my chain length and bingo.