Enduro / DH
Gavia
Nine gears, oversized internals. Built for gravity.
9 gears · 428% range · 2,110 g · 300 Nm input
The Gavia is the gearbox for riders who measure drivetrains in seasons of abuse, not grams. It carries nine gears across a 428% range with internals sectioned for sustained descending: wider gear faces, doubled shift dogs, and an output bearing sized for repeated hard landings rather than smooth pedaling loads.
A gearbox makes its strongest case on a gravity bike. Removing the derailleur removes the most fragile component on the frame, and removing the cassette pulls more than half a kilogram of sprung mass off the rear axle. The rear suspension tracks noticeably better — less unsprung weight, no chain slap through a clutch derailleur, and a chainline that never moves under compression.
Like every Helicala unit, the Gavia is machined from 7075-T6 billet in Charlotte and sealed against water, grit, and pressure-washing. Shift quality on day 300 is the same as day one, because nothing that determines shift quality is exposed to the trail.
Specifications
| Gear count | 9 |
|---|---|
| Total gear range | 428% |
| Step between gears | 19.9% avg |
| Unit weight (incl. oil) | 2,110 g |
| Max input torque | 300 Nm |
| Housing | CNC 7075-T6 aluminum, ribbed |
| Lubrication | Sealed oil bath |
| Service interval | 10,000 km oil change |
| Interface | Helicala TM splined mount |
| Shifter compatibility | Trigger or grip, cable-actuated |
| Drive output | 30T cog, chain or belt |
Engineering notes
The Gavia trades gear count for section thickness. Gears are 18% wider than the Stelvio's, shift dogs are doubled, and the output shaft runs on a larger-bore needle bearing rated for repeated landing loads. The 300 Nm input rating is a continuous figure, not a peak — the unit is validated against impact spikes well above it.
Wider 20% steps are deliberate: in steep terrain you want decisive ratio changes, not a hunt through half-steps. First gear is low enough to climb back up the hill you just rode down.
Compatible frame standards
- Helicala TM mount
- Six-bolt splined interface, published as an open spec for frame builders.
- Pinion P-line bolt pattern
- Direct fit to frames designed around the Pinion P-line bridge via adapter plate.
- DH chain device
- ISCG-05 tab adapter for upper guides on park and race builds.