Tomos A35/A3 sprocket ratio

January 20, 2026 Laurens JMPB

If you ride a Tomos, you know that sprocket ratios play a major role in how your moped performs.
Whether you’re aiming for top speed, pulling power, or a comfortable all-round setup, the right combination of front and rear sprockets makes all the difference.

Standard sprocket ratio

The original factory sprocket ratio of a Tomos is usually:

Moped (25 km/h):

• Front sprocket: 26 teeth

• Rear sprocket: 33 teeth
  → Ratio: 1:1.27

Moped (45 km/h):

• Front sprocket: 26 teeth

• Rear sprocket: 22 teeth
  → Ratio: 1:0.85

The 25 km/h ratio is focused on smooth riding and pulling power, while the 45 km/h ratio is clearly tuned more towards top speed.

What happens when you change the ratio?

By changing the sprockets, you can fine-tune your moped to match your preferences:

More teeth at the front (e.g. 27T or 28T)

• ➕ Higher top speed

• ➖ Less pulling power

• These sprocket sizes are not a direct fit (due to crankcase clearance)

Fewer teeth at the front (e.g. 24T or 25T)

• ➕ More pulling power

• ➖ Lower top speed

Fewer teeth at the rear (e.g. 31T or 28T)

• ➕ More speed

• ➖ Less power at low rpm

More teeth at the rear (e.g. 33T)

• ➕ A lot of pulling power

• ➖ Lower top speed

Commonly used combinations