From my experience, the Ovaltechs will NOT give an even chain tension. I built a single speed for my wife on a bike that came with a 42 tooth Ovaltech as the inner ring. At one point of the rotation, it would be bordering on completely binding the chainring, while at another point it would be so slack that you could see the chain bouncing around. Currently, I'm running a chain tensioner on them, and you can see the range that the arm has to cover as she peddles the bike.