Does 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 crank rotation sooner. The benefit of this is twofold; increased gearing on the downward stroke and faster crank speed to get the crank propelled back around into the power phase continually. This is a significant gain because virtually all studies into pedalling performance suggest that a minimum 80% of your power comes from the downward motion. Mainly because much larger muscle groups are used for this motion. The physics sorcery adds extra power in the downwards stroke for no extra effort by reducing the dead spot and adds a bigger gear for the now larger power phase in the downward stroke. Win, win. All of our Chain Rings are + / - 2 Teeth so; 30T Has a combination of 32T Increased Power Phase and 28T Dead Spot 32T Has a combination of 34T Increased Power Phase and 30T Dead Spot We would recommend sticking to the current sized round ring that you are currently using when selecting your Oval size. SPECIFICATION Thick Thin Tooth profile with Mud Bleed. 10 11 and 12 Speed Compatible. 115 Degree's of Ovality. Fully CNC Machined from 7075 Aluminium.