Seiko SPORK 4R15 Diver SRP043K2 LNIB 99% 235 SHIPPED paypal USA.

Ditchdoc wrote:Anybody know the practical difference in the 4r15 and the 7s26?

Watch Noob wrote:

Ditchdoc wrote:Anybody know the practical difference in the 4r15 and the 7s26?

From what I've researched Ken, you lose the Day function with the 4r15, both are still shake and bakes, so I'm not sure what else in practically you actually get from the movement. I haven't compared reserve times so maybe there's something there.

Ditchdoc wrote:Anybody know the practical difference in the 4r15 and the 7s26?

The power reserve is greater and the winding rotor is supposedly quieter.

With the 4r15, it is likely that a little regulation is done at the factory, making use of the adjustable stud carrier and the adjustable regulator roller pins. Add that to the new mainspring with it's longer reserve and it is easy to see tighter performance specs. But with the same attention, the 7s26B could be made to meet the tighter specs as well.