The Speed timer is a product line of Seiko’s automatic chronographs from the 1970's. Speedtimer branded watches - 6138/6139 - were mechanically the same as their regular counterparts, but had small stylistic differences that set them apart from the general production of the same watch. They were built in far lesser numbers and offered in fewer markets than their normally aspirated variants. As such Speedtimer are highly priced amongst collectors. It is important to note that not all Seiko chronographs had a Speedtimer variant. A note on Speedtimers....at one time it was determined that one of the variants. I think it was the 6139's had the "b" movement with the extra jewels. Not true with the 6138's though. There is also the issue of whether or not Speedtimers were domestic [Japan] only models.
This watch uses the 6139B movement. It is a 17 jewels automatic single register chronograph movement and has no seconds hand. The orange chrono-seconds hand came original, just like red and yellow. The hour/minute hands are very often redone or replaced, because of the lume I suspect. There is an ideal distribution of the black, green and silver, which is quite intuitively discernible. They just seem wrong or right. I won't bother here to calculate the distribution.
The seconds hands on the subdial, it is quite different than the Seiko Pogue for instance in that the hand overlaps the markings. Also the subdial should neatly touch 7 of the minute markings on the main dial. There are endless details to be discussed on the dial, if you are looking to buy.
Covering the dial should be mineral glass, called Hardlex, around the dial should be an inner white chapter ring with tachymeter indices. The pushers are not adorned in any way, straight pokers them. It's a column wheel chrono and they do tend to clunk in a little - the spring pressure needed for operation is quite high - as with the other 6139 chronos like the Seiko Pogue. The bezel has a nice high gloss polish to it. On top it is flattened where it meets the crystal. Many after market or restored bezels have this rounded off, as you can see in the pictures above. Below, you can see the stormtrooper as it is supposed to be. The case should have crisp edges and the crown must be recessed. The crown of course, for this type of chrono, accesses the day/date function - just push it to quickset.
The 1960s saw many in the watch industry looking to capitalise on an increased demand for automatic watches. In 1969, Seiko delivered by introducing what was arguably the world’s first automatic chronograph, the Seiko 6139. This article focused on its earliest incarnations, the 6139-600X and 8050. A watch often called the “Speed-Timer”. Seiko printed the term “Speed-Timer” on many of its early chronographs destined for the Japanese market, indicating the more advanced features, such as a thirty-minute chronograph recorder, a day and date indicator, and a tachymeter scale. Production of the 6139 line up ended sometime in 1978, but are still readily available today. The 6139-600X and 8050 series are quickly becoming very collectable pieces thanks to a combination of great design and a storied history. The 600X of course has two big claims to fame, as both a contender for the world’s first automatic chronograph to achieve serial production and as the first chronograph worn in space.