Orient Star Retro-Future Bicycle Watch

A History of Orient's Use of Power Reserve Indicators

Power Reserve indicators have become a common feature in many Orient
watches. It is a mechanical complication that not only adds functionality that
is often useful, but can also enhance the appeal of a watch dial, make it more
interesting, or visually balance other dial elements such as the date or small

In this article, we will explore the mechanics of the PR indicator, and
the history of its use by Orient.

How Does A Power Reserve Indicator Work?

The power reserve indicator was first introduced in a wrist watch by
Jaeger LeCoultre, with Caliber 481. Interestingly though, the watch you'd
currently see if you visit the Wikipedia page forPower Reserve Indicator, is an Orient (and it wasn't me who put it
there, I swear!)

The mechanism itself is not too sophisticated, in comparison to some
other watch complications. Without diving into too many technical details, the
PR indicator generally provides a measure of how wound the mainspring is. This
is done via an additional module that connects to the mainspring barrel.

There are a number of different modules that can produce a PR
indication. One popular method is via a differential gear, where the many
rounds of winding up (or un-winding, down) are converted through a number of
gears to a smaller turning angle, so that one might see the entire range from zero
to full winding in something around 90-120 degrees, typically.

Another method is via a differential (i.e. tapering) screw, where the
turning of the barrel would cause the screw to move up or down over a small
distance, again enabling easy reading of the remaining power.


Orient's First PR Indicator Model

Orient introduced its first PR indicator-equipped movement in 1996, as
caliber 46F. It was initially included in a series of Orient Star models
generally known as EW00, with a follow-up series of similar design known as

Caliber 46F was a 21-jewel movement, featuring 21,600 vibrations per
hour like most Orient movements, and offered a 40-hour power reserve. Its
stated accuracy was within +25/-15 seconds per day. It only had automatic
winding – so owners could not experience the satisfaction of winding the watch
using the crown and watching the power reserve needle go up…

These early models were time-only pieces, and did not include a date or
day mechanism. If you are interested in acquiring one of these references,
please note they are fairly small, with a case measuring about 35mm across,
without the crown.

Soon after, Orient followed up and introduced non-Star models containing
the same movement and generally very similar features, as the EW03 series. Yes
– some of those did feature cathedral hands… this is authentic.


Other Power Reserve Models

The power reserve indicator quickly became popular, and the brand added
more calibers with additional features. Such was caliber 46G, which added a
date wheel and in 1997 became the heart of the all-new M-Force.
That watch boasted the advantages of its mechanical movement over the
then-prevailing quartz movements, and thus highlighted its power reserve

The following table lists the various 46-series PR movements.

Orient continued to make use of power reserve indicators in later
generations of its movements, such as in its series 40 and 48, and more
recently in its F6 and F7 series movements.


The Power Reserve Indicator, Today

Throughout 2020, Orient faded out the use of PR indicators in regular,
non-Star models, and has apparently decided to keep them as a unique feature of
its Orient Star line.

Regular Orient models will have to do without this complication we grew
so much accustomed to. Even the M-Force, a watch so strongly tied to the
essence of the Power Reserve, had to bid the PR indicator farewell in its latest

With Orient Star, though, it's business as usual. The Power Reserve
indicator was at center stage recently as the brand unveiled
its latest Skeleton model
with the new F8 movement, now offering 70
hours of power.

Photos of EW00, EW01, EW03 series, are taken from old sale ads. Other photography is copyright of Orient Place blog.