Ronda 9138

 
Ronda 9138

Ronda 9138

Description

A rather rarely used ladies’ caliber is the Ronda 9138, which was later available under the brand name “Harley”.

The 9138 is on top of the Ronda movements in terms of features and quality. It has got a true swiss palett anchor escapement, an Incabloc-secured balance, beating with 21600 A/h and 25 jewels altogether. The rotor winds unidirectionally; on manual winding, the mechanism is not released, so that the last wheel spins very fast. Only the rotor is detached from the gear now.

Ronda 9138 without oscillating weight

Ronda 9138 without oscillating weight

The date mechanism advances slowly within the last 90 minutes of a day, but can be quickset on the second position of the crown.

This movement is not yet listed on the Flume K3 from 1972, but appears on the list of all Ronda movements from 1976, so that it’s release year can be estimated quite well. It might have been producted till the eigthies based on the fact, that the “Harley” name appeared just then and might be mostly well known because of the micro rotor caliber 2538.

Ronda 9138 dial side

Ronda 9138 dial side

Technical data

Manufacturer:Ronda
Caliber:9138
Number of jewels:25
Escapement:Pallet lever
Balance types: Nickel anular balance
Shock protection(s): Incabloc
Balance bearing / direction hairspring:Counterclockwise
Moveable stud:yes
Adjust mechanism:Hairspring key
Winding mechanism:yoke winding system
Features:SCD,QG,RDR,AUT
Functions:hour, minute, second, day, selfwinding
A/h:21600
Size:8 3/4'''

Usage gallery

Grovana Automatic ladies' watch

Grovana Automatic ladies' watch