With Cannondale's release of the new OPI MTN SpideRing SL, System Integration takes one step further. The OPI SpideRing is CNC machined from a single block of aluminum, and combines spider/chainrings/bolts into a single work of art. Weighing a mere 60g for a 30t unit, these elevate the Hollowgram crankset into the ultimate combination. Available in 30-34 tooth counts, and in both Si and Ai offsets.
Not sure what ring offset you need?
Si: Chainring has an offset (dish) which brings it in towards the frameset. This is the most common configuration, and is used on all Scalpels up to 2016, F29 Hardtails, Jekyll, Trigger and Habit.
Ai: Chainring has very little offset (dish) which appears flat. This is the new system on the F-Si and 2017 Scalpel Si.