. It is quite rare to see keyless works on the bridge side of the movement and is facilitated in this case by the absence of manual winding capability. By placing the clutch lever, set lever and detent where the crown wheel would usually be, the space on the dial side can be used for the quickset mechanism alone. This allows all of these components to be quite a bit beefier than they would be otherwise. The increased size of these levers and wheels adds to their robustness as well as their ease of manufacture, owing to the looser tolerances required. The set lever has a three-position detent and pivots on a post, rather than a screw. It's tail end serves as a push-button to release the stem from the movement and can only be operated when the stem is in the neutral (1st) position. Most keyless arrangements have one position in which it is most convenient to! replace the stem, it is nice that the 7S26 dictates this by only allowing the stem to be removed in one position. The set lever acts as its own return spring by way of its extended tail. This does away with the need for a wire spring, none of which are found in the 7S26.
The click  on the 7S26 is also remarkably simple. It consists of a long steel spring held in place by sheer geometry, without the use of screws. It lies under the click wheel and is held in place by a brass pin on one side, a raised portion of the mainplate on the other and the ¾ plate bridge on top. The barrel  is circular grained on the top and bottom and is replaceable as a whole unit. Although it is possible to open the barrel, it is not designed with this in mind. These pictures [18,19] are of a faulty barrel my friend Randall Bensen encountered. Inside we can see the insufficiently applied black graphite-laden grease . He replaced it with a whole new barrel (an appropriate precaution given the permanently sealed nature of these barrels) and proceeded to open up the bad one. After he took the mainspring out and cleaned it, we can see that the inner surfaces of the barrel are unfinished . While this will undeniably effect the consistency of the ! power flow from the mainspring, a host of other refinements throughout the train and escapement would be necessary before evidence of this effect could be noticed.
The power train of the 7S26 is a direct-seconds layout of the simplest configuration
. Quite remarkable for a low-cost movement such as this, are the Diafix cap jewels on the third wheel and escape wheel . These jewels bring the total number to 21, quite sufficient for an automatic watch, especially with only two jewels in the automatic system (for the intermediate wheel). The power train wheels are crudely finished and appear to be made of nickel. This is the first time I've seen nickel train wheels. Traditionally, train wheels are made of brass because it is relatively strong, cheap, easily machined and wears well in contact with steel. Nickel has these same features while being slightly stronger and more difficult to machine. It's use for train wheels does not seem to be dictated by cost so I can only surmise that its greater strength is desired.
All of the train wheels have properly shaped teeth although their faces are not well polished with the exception of the escape wheel. The center wheel  is actually a solid disk, having no spokes or even holes drilled through it (as do some train wheels in earlier movements). While this is not ideal from the standpoint of inertia, the second wheel is the slowest moving of the four train wheels, making its inertia the least critical. Disconcertingly, the lower pivot on the third wheel was completely flooded with oil . There was so much oil present that it had contaminated the teeth of the center wheel  and would have resulted in serious wear issues, over time capturing the inevitable micro-metallic dust and turning it into an abrasive paste. Apparently one of Seiko's robots was asleep at the wheel when applying lubrication to this pivot.
The escape wheel teeth , while appropriately polished, are not beveled at all, leaving a rather wide face to impulse the pallet jewels. This means more friction and less power. One possible reason for these wide impulse surfaces is to prolong the life of the pallet stones. The wide faces of the escape wheel teeth are less likely to groove the pallet stones even after years of use. Seiko escapements also seem to have an unusually large locking depth (the extent to which the pallet jewels lock the escape wheel teeth). In all likelihood this is a concession to looser tolerances in the manufacturing process and in my experience often results in a lower balance amplitude.
The pallet bridge  is nicely shaped and supports a very homely pallet lever . The topside of the pallet appears to have had its insides scooped out and is utterly unfinished. Interestingly, the underside of the pallet fork is fairly well polished, contrasting with the Swiss tendency to finish the top of the pallet fork and not the bottom. At least I can say they weren't trying to hide anything. I can only guess that the weird, semi-hollow form of the pallet fork is an attempt to make the pallet fork lighter, something that is highly desirable in this critical component.
The balance itself  has two arms and is of unknown composition. If I had to guess, I'd say it was made of a nickel alloy and the hairspring is made of some form of elinvar. It is not as critical for the balance to be made of a material that is stable over different temperatures as the hairspring, but without a variant of elinvar for the hairspring, it would be impossible for the movement to perform well in daily use. The hairspring is flat and is attached to the collet  in a manner that avoids the problems inherent in traditional pinning methods. A pinned hairspring has its elasticity compromised in close proximity to the pinning point as the spring's cross-section curves around the pin. In addition, the hairspring must be bent profoundly from its even, concentric spiral shape to where it enters the collet. Seiko's arrangement does away with both of these problems as the inner coil of the hairspring is crimped in a groove in the collet without disturbing its! shape. The outer coil of the hairspring is similarly crimped in a slot in the stud . Although this is a perfectly functional solution, it negates the possibility of altering the length of the hairspring in the future, resulting in a balance that is effectively disposable.
The regulator uses a buckle  (as opposed to simple pins) to keep the hairspring from slipping out when subjected to shocks. Like all of the components of the movement, it is crudely made but well designed and functional. A watch is said to be "in beat" if the tick and the tock are equally distributed around the resting position of the balance and this is controlled by either rotating the hairspring collet on the balance staff or changing the position of the stud. For ease of beat adjustment, the balance cock of the 7S26 features a movable stud carrier that I fault only for being a little too large. Its excessive, unbalanced weight can cause it to shift during shipping or when dropped, resulting in a significant rate change as well as throwing the escapement out of beat. If the escapement goes too far out of beat, its ability to self-start after running down will be hampered in addition to positional performance problems.