Move the drivetrain inside.

Sealed planetary gearbox transmissions for performance mountain bikes. Designed and machined in Charlotte, North Carolina.

Explore the lineup
Macro view of gear oil pouring over the steel teeth of a Helicala gearbox gear

Sealed gearbox

Every gear pair runs in an oil bath behind double-lip seals. Nothing that determines shift quality is exposed to mud, grit, or a pressure washer.

Trail-tuned ratios

Even steps and up to 568% total range, tuned per model — tight steps for climbing cadence, wide steps for gravity.

Shift under load

Helical-ramp engagement completes a shift at full pedaling torque — or at a standstill, before the corner exit.

Stelvio 12-speed gearbox unit in terracotta anodized aluminum, drive side with splined input shaft

Featured · Trail / All-Mountain

Stelvio

The trail gearbox. Twelve gears, sealed for the long haul.

12 gears
510% range
1,885 g
250 Nm input
Learn more

Technology

One oil change every 10,000 km. That is the entire maintenance schedule.

Read the engineering →

About

A small company with a narrow focus.

Helicala exists to do one thing: build mountain bike transmissions that move the complexity of shifting inside a sealed housing, where it can be engineered instead of endured. We design, machine, and assemble our gearboxes in Charlotte, North Carolina, in small batches, and publish our mounting interface as an open spec.

Read our story →