ETA 7750-8290 Friction Spring

Product Description

The ETA 7750-8290 Friction Spring is a genuine Swiss-made component designed for the ETA/Valjoux 7750 automatic chronograph movement. Pre-assembled for the chronograph wheel, this spring compensates for play in the chronograph wheel teeth, ensuring smooth and precise chronograph hand movement. It is typically replaced when chronograph hand irregularities or excessive amplitude drops are observed.

Features & Function

• Genuine ETA/Valjoux part – authentic Swiss-made component for the ETA 7750 movement

• Chronograph mechanism component – pre-assembled for the chronograph wheel

• Compensates gear play – ensures smooth and precise chronograph hand movement

• Direct replacement – drop-in replacement for worn or damaged friction springs

• Precision-engineered – manufactured to ETA’s original specifications

Specifications

• Part Number: 7750-8290

• Compatible Movements: ETA/Valjoux 7750, 7751, 7753, 7754, 7760, 7765

• Function: Friction spring for chronograph wheel (compensates gear play)

• Movement Diameter: 30.0 mm 

• Movement Height: 7.9 mm 

• Jewels: 25 

• Frequency: 28,800 vph (4 Hz) 

• Power Reserve: ~44–48 hours 

• Origin: Switzerland (ETA factory part)

• Condition: Brand new

Applications

• Service and overhaul of ETA 7750-series movements 

• Chronograph mechanism repair – replacing worn or damaged friction springs

• Chronograph hand irregularity correction – resolving jumping or unsteady chrono hand movement 

• Amplitude restoration – addressing excessive amplitude drop during chronograph operation 

• Suitable for professional watchmakers and experienced repair technicians

FAQs

1. Is this a genuine ETA part?
Yes, this is a genuine ETA factory part (reference 7750-8290), made in Switzerland. It is not an aftermarket or generic copy. 

2. Which movements is this friction spring compatible with?
This friction spring is compatible with the ETA/Valjoux 7750 and its variants, including 7751, 7753, 7754, 7760, and 7765. 

3. What is the function of the friction spring?
The friction spring compensates for play in the chronograph wheel teeth. Insufficient tension can cause irregular chronograph hand movement, while excessive tension can lead to amplitude drop and reduced power reserve. 

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