The caliber 4R36 is one of Seiko’s workhouse movements. This is a technical review of the Seiko 5 Sports Ref. SRPD77 and the caliber 4R36 which powers it. Giving the break down is master watchmaker Jordan P. Ficklin, who explains if the movement rate can be improved on, and a way to straighten a misaligned chapter ring.


Produced by Jordan P. Ficklin.

Posted by:Jordan P. Ficklin

Jordan P. Ficklin, CW21 is a certified watchmaker of the 21st century. He graduated from the Lititz Watch Technicum with a WOSTEP diploma in 2006. He is a co-owner of the Cincinnati Watch Co, designing and assembling watches in Cincinnati, Ohio, and the owner of Cincinnati Watch Repair, an independent watch service center meeting the needs of the microbrand and collector communities.