Our premium 1X Cannondale Hollowgram direct mount Oval chainrings are designed for Hollowgram crank family. This also includes the new FSA modular MTB cranksets Compatible with old and newest models. Size (Mass +/-1g): - 30T(61g), 32T(66g), 34T(72g) Compatibility - Cannondale Hollowgram Si, SiSL, SiSL2. chain: 9, 10, 11 and 12spd Eagle compatible. Material - cnc machined 7075 Txxx Aluminum. Long-lasting construction Chainline - 47-50mm (5.7mm offset). Chainline depends on the length of the axle you use and spacers configuration. Ovality - Optimized to each size separately. Range: 10.2-14.4% and Timing of 110.5-116.3° after TDC (top dead center) Our Cannondale Direct Mount oval chainrings are designed with an offset that works best with Cannondale Ai-drivetrain (FSI). When used on non Ai / FSI Frames, our direct mount oval has 3mm less offset than original, non-Ai Cannondale chainring/spider. So in order to achieve perfect chainline, you will need in this case, to change the spacers on the BB axle and move right side crank closer to the frame. This is an easy task and sets the crank in very good position in relation to the frame.