Osymetric O-14 5 Arm Chainring 110mm BCD $164.50
Stop pedaling in circles.
How many times have you heard the phrase, "Scrape your cleat 'across' the bottom of your pedal stroke"? Or, "Round out your stroke"? It's all in the name of getting the most power to the drivetrain throughout every phase of the pedal stroke. Osymetric has designed a chainring that addresses the deficiencies in the stroke, so you spend more time riding and less time analyzing every degree of every stroke. The O-14 5 Arm 110mmBCD Chainring will have you pedaling around other riders' "circles."
While an ovalized ring maximizes the power part of the stroke, the dual-cam more effectively minimizes the dead spot in the pedal stroke. The Osymetric chainring is the brainchild of French engineer Jean-Louis Talo. The somewhat oddly-shaped chainrings use a dual-cam design, with each cam lobe corresponding to the most powerful part of the pedal stroke: the downstroke. The design increases the gear inches of the chainring at the point where you’re able to apply the most force, but as you transition to your least powerful part of the stroke, or dead spot, the chainring reduces in size to speed you back into the power part of the stroke. For instance, an Osymetric 52-tooth chainring would be similar to a 55-tooth in the largest portion of the cam, then gradually reducing to a 49-tooth over the dead spot. This translates to a claimed 3% increase in speed. While having a rounded pedal stroke is nice, most riders never perfect it. Osymetric assists where human physiology fails.
To install the chainrings, you'll need to make adjustments to the derailleur height and width, with the included screw. And you'll also need to spend time fine tuning the rear derailleur. The first ride may seem a bit awkward, but after a few times out you'll feel more power in your stroke and be less aware of any inconsistencies in chainring shape.
The Osymetric O-14 5-Arm Chainring fits any 5-bolt crankset with a 110mm BCD. It is available in 38t, 50t, and 52t.