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 that powers it. Giving the breakdown is master watchmaker Jordan P. Ficklin, who explains if the movement rate can be improved, and a way to straighten a misaligned chapter ring.

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.