Reducing chain bounce is a crucial need for today’s riders that frequently venture off smoothly paved roads. SRAM’s Orbit™ technology, used in SRAM RED and Force eTap AXS rear derailleurs, limits chain bounce by controlling the chain’s downward movement when riding over bumps.
Orbit is a new, patented design that consists of a silicone fluid damper with a one-way valve that controls the rear derailleur cage’s counter-clockwise rotation. This prevents the lower derailleur pulley from moving forward when bumps in the road cause g-force spikes that pull the chain downward. The damped cage rotation keeps the drivetrain quiet and helps prevent the chain from derailing off the chainring.
The beauty of the lightweight Orbit fluid damper is that it is speed sensitive—meaning, the harsher the bump, the more resistance it applies to keep the chain under control. So, when the derailleur cage rotates counter-clockwise slowly—as it does during a downshift to an easier rear—the damper offers so little resistance, it’s as if the damper isn’t there. This allows you to get the benefits of a mechanical friction-style clutch when you need it, without the excessive chain tension these clutch types provide when you don’t. It’s the best of both worlds. And it’s a maintenance-free design so you spend less time wrenching and more time riding.
What if you could add range to your drivetrain while also smoothing the gear progression with smaller differences in tooth count between neighboring gears? And what if you could gain that without losing drivetrain efficiency or having to replace your chain more frequently? Our unique Flattop chain link design is a key element that makes all of these improvements possible.
To gain a wider gear range with smaller gearing steps, the chain has to get narrower. With Flattop, we’ve added material on the flat side of the chain plates to strengthen every link. The Hard Chrome surface treatment on the pins, inner plates, and rollers also extends the life of the chain and keeps it shifting precisely over the long haul. Additionally, Flattop chains feature longer wearing large diameter rollers that help deliver the same drivetrain efficiency as our 11-speed drivetrains. All of these technologies together have enabled us to engineer a narrower 12-speed chain that lasts 36% longer than our 11-speed chains.
With the Flattop chain design it’s like having your cake and eating it too… except this cake actually helps you to be faster on the bike… and you don’t have to buy cake as often… There might be a better metaphor to explain it, but we like cake, so we’re sticking with it.