Burgtec Shimano Direct Mount Oval Thick Thin ChainringDoes a mechanical advantage of increased gearing sound Interesting? If so, read on. Through research and testing of many different prototypes with varying amounts of Ovality we found 115% (from the top centre) to be the optimum. This shrank the dead spot suitably and gave the same flawless chain retention as our round rings. The shortening of the dead spot on the top and bottom of the power curve allows you to get back into the power phase of your