The Burgtec Oval ThickThin 104 PCD Chainring come after a year full of testing to ensure this is the best chainrin possible. This shrank the dead spot suitably and gave the same flawless chain retention and silence 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 down ward motion. Mainly because much larger muscle groups are used for this motion. The physics sorcery essentially adds extra power in the down wards 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.  Burgtec Oval ThickThin 104 PCD Chainring Features Thick Thin Tooth profile with Mud Bleed 10 11 and 12 Speed Compatible 115 Degree’s of Ovality Fully CNC Machined from 7075 Aluminium