Being an owner of both the Citizen Promaster Eco Drive E2100 and Seiko Sportura 7L22 Kinetic chronograph, I thought a comparison between these two distinct yet similarly featured movements would make an interesting subject.
Why am I comparing these two movements? Well, for starters they are both quartz-controlled watches with unique, mechanically actuated chronograph functions. These two hybrid calibers are also mainstream calibers and both companies have manufactured numerous models based on them.
The most glaring difference between the Cal 2100 and the 7L22 is that the former is solar powered while the latter is a motion powered movement.
Let’s examine the merits and demerits of both animals.
The Citizen Cal 2100 Eco Drive
Citizen has been concentrating on their Eco Drive range of watches and it looks like they have not only perfected their solar powered watch technology, they are also producing more and more models based on their Eco Drive movements.
Although Citizen still makes automatic watches it appears that (unlike Seiko) they’re not interested in pushing their automatic movements into the high end range bracket. Most of their automatic movements are found in their NY-series diver’s watches and some of, their Oxy sub-brand watches.
The company also makes low, medium and high grade quartz movements through its Citizen Miyota manufacturing facility. Citizen also has a sub-brand under the name “Q&Q" which are very low cost quartz watches targeted to mostly Asian and Middle Eastern markets.
On the opposite scale, Citizen produces high end quartz calibers for their Chronomaster models (also dubbed “The Citizen"), which is a high accuracy, thermocompensated quartz watch and complicated quartz movements for their exotic Campanola line.
Two Citizen E2100 chronographs side-by-side: the CTZ66-0471 “Bullhead" (left) and an AV0037-55 (right). (Borrowed photo)
The Caliber 2100 is indeed Citizen’s breakthrough chronograph movement. Instead of employing conventional electronically controlled chronograph mechanisms used in conventional quartz chronos, the 2100’s stopwatch is mechanically actuated. Timekeeping is still quartz but operation of the stopwatch is done by mechanical means, just like an automatic chronograph.
In other words, with the Cal 2100 you have a watch that is as accurate as a quartz but with the feel of an automatic chronograph. The Promaster AV-series chronographs are probably the most widely recognized Cal 2100 models and there are specific variants made for the U.S., Japan, Europe and Asian markets.
Citizen spent a lot on advertising to push their Cal 2100 models into the market and touted them as the “Ultimate Chronograph". I couldn’t agree more as I think it’s the most complicated quartz-controlled chronograph watch I’ve ever seen.
Here’s a short video ad of the Cal 2100 if you’re interested to watch.
The Seiko 7L22 Kinetic
Seiko, always at the forefront of watchmaking technology also experimented with hybrid mechanical chronograph movements.
Following their triumphant engineering excellence with their inaugural Kinetic chronograph, the very expensive Seiko 9T82 caliber, Seiko decided to make a mainstream Kinetic chronograph caliber for the masses without the cost and complexity of the 9T82 caliber.
Their engineers were faced with a daunting challenge to come up with a completely new caliber at he lowest possible design and production cost. Instead of designing a caliber totally from scratch, Seiko’s designers decided to use components from their existing calibers to save design and manufacturing costs.
Thus the more affordable 7L22 caliber was born. This new movement borrowed the power generation unit from their existing 5M62 Kinetic caliber and its geartrain was taken from the proven 7N-series quartz caliber. The 7L22 movement is also produced in Japan but unlike the 9T82, it is not individually hand assembled.
The 7L22 also carried forward the unorthodox design elements from the 9T82 but with the perpetual seconds housed in its own subdial. For a further detailed explanation of the 7L22’s dial design, read this excellent article written by “Tempus Fugitive" in the GMT+9 watch blog.
Seiko debuted the 7L22 with their Arctura SNL001P model in early 2003 for the international market with high profile advertising and promotion.
Above: An early Seiko ad for the 7L22 based SNL001P and the actual watch (right)
Meanwhile for the home Japan market, Seiko also introduced the 7L22 into its domestic Prospex and Brightz lineups. The 7L22 caliber became quite successful in terms of sales that Seiko also included the 7L22 models into their Sportura, Ignition and Premier range of watches.
The most expensive 7L22 models are the ones from the Brightz range while the least expensive are from the Arctura lineup.
International market 7L22s: Arctura SNL009P, Sportura SNL017P and Premier SNL042P
Japanese Domestic Market 7L22s: Brightz SAGE007, Ignition SBHV003 and Prospex SBDV003
Comparisons: Cal 2100 vs Seiko’s 7L22 Kinetic
It may interest you that Seiko also has a formidable hybrid chronograph, in the form of their well known 7L22 caliber, Kinetic chronograph. The Seiko’s stopwatch is actuated by a heart-shaped cam which snaps the stopwatch hands instantly to zero.
In my opinion, the Cal 2100’s chronograph is much more superior to Seiko’s 7L22 in terms of features but the latter has better aesthetic looks than Citizen’s 2100.
|Feature||Citizen Cal 2100||Seiko 7L22 Kinetic|
|Power source||Light powered||Motion powered|
|Accuracy||+/- 15sec per month||+/- 15sec per month|
|Power reserve||8 months||5 months|
|Calibrated elapsed time||12 hours||45 minutes|
|Maximum measurable time||12 hours||48 minutes|
|Accidental reset inhibitor||Yes||No|
|Automatic chrono reset||No||No|
|User adjustable chrono hands||No||No|
|Automatic watch-like feel||No||Yes|
|Main time layout||Main dial||Subdial|
|Different models available||Limited||Many|
In my opinion, the 7L22 is more form over function while the 2100 is a more practical chronograph. With a maximum timing capability of up to 12 hours, the Citizen Promaster E210 is far more useful for timing long events.
On the other hand, Seiko’s unique layout of the 7L22 restricts its stopwatch to just 45 minutes of timing (although the chronograph stops at exactly 48 minutes) and I don’t think a three-quarter hour limit is practical for use in real life. For short events like timing sporting activities, the 7L22’s chronograph serves adequately.
The Cal 2100 also wins handsomely in the power reserve department. When both are fully charged, a Promaster E2100 will continue to run for 8 months while Seiko estimates their 7L22 just up to 5 months of operation. I’m not sure if the difference lies in the power consumption of the movements or the total capacity of their internal rechargeable cells.
In addition, Citizen’s engineers also made it impossible for the wearer to accidentally reset the chronograph while timing is taking place. It’s like a non-flyback automatic chronograph – you cannot push both buttons at once nor can you reset the stopwatch before stopping it.
Somehow, in possible hindsight Seiko’s engineers unfortunately did not incorporate a reset inhibitor into the 7L22. Which means, not only you can accidentally push the reset button while timing is in progress – it’s also possible to press both stopwatch buttons simultaneously. Damage can result to the mechanism if either happens and this is highlighted as a warning in the Seiko 7L22 owner’s manual.
Personally, I’d feel safer with the Cal 2100’s stopwatch mechanism. With the Seiko 7L22, I’ll have to remember to stop the chronograph first before resetting it.
Quirks of both calibers
Limited stopwatch timing
Both calibers are not free from their down sides though. Unlike true mechanical chronographs whose stopwatches will run continuously so long as their main springs have sufficient torque, both the Cal 2100 and 7L22 have finite time measurements. As I’ve mentioned earlier, the Cal 2100 measures up to 12 hours while the 7L22 is good up to 48 minutes.
This time limit also serves to safeguard both the watches against accidental power drain in case you store the watch in the drawer for a long time with the stopwatch still active.
No automatic reset
Unlike conventional quartz chronographs, there is no automatic reset when the maximum elapsed time has reached. You’ll have to manually stop the chronograph and press the reset button for the next event timing.
No fine adjustment of chrono hands
More importantly is that both calibers behave more like automatic chronographs than quartz ones. There is also no provision for fine realignment of the chrono hands by the user should the hands don’t reset to zero properly. Many quartz chronographs allow micro tweaking of the stopwatch (in Seiko’s case, all of their quartz chronographs allow for such adjustments) in case the hands drift.
Sudden impacts and shocks while the stopwatch is running can affect the alignment of the stopwatch hands. That said, both calibers are also prone to the occasional self-misalignment. Should this happen, your only recourse is to take the watch to the repair center.
Therefore you should treat the Promaster E2100 and Seiko 7L22s carefully like mechanical chronograph watches.
No provision for split or lap timing
Unlike conventional quartz chronographs, there is no provision for briefly pausing the chronograph for split or lap time measurements. With a quartz chrono, when you measure the split or lap times, the sweep chrono hand will pause briefly until you resume timing. An internal clock keeps track of the current elapsed time and when the stopwatch is resumed, the chrono hands will catch up with the actual time.
No such thing with the E2100 or the 7L22. You can only start, stop and reset the chronograph – just like a non-flyback mechanical chrono.
It’s difficult to conclude whether the Cal 2100 is much more superior than the Seiko 7L22. It depends from which angle you’re looking from. If you intend to use the stopwatch frequently and you’re not the active sort of person, the Cal 2100 would be the better choice.
All the Citizen Promaster E2100 models are very large timepieces and their stainless steel models are considerably heavy. If comfort or large size is a negative issue for you, consider a Seiko 7L22 Kinetic instead.
Seiko makes more models based on the 7L22 than Citizen with their Cal 2100 so there are more choices for you, from the most affordable international model Arctura to the expensive, Japan market Brightz. On the other hand, all 7L22 Seikos have small main time clocks, if you have a problem with reading small dials the Kinetic Chronograph isn’t for you either.
As for me, I’m the very inquisitive type of person so I ended up buying a Promaster E2100 and a Sportura 7L22. I like the Sportura for its sporty and flashy looks with the feel of an automatic watch while I like the Promaster for its elegant appearance and its 12-hour stopwatch.
Two of my favorite chronographs: the black Citizen Promaster AV0037-55 (left) and Seiko Sportura SNL035P (right)