hanski 40 Posted July 19, 2018 Being frustrated that my JKF 1680 Sub required glue to hold the crystal and retaining ring in place I decided to replace with something friction fit I ordered a couple crystals and a bezel assembly. I started out with a JKF 1680 Red Submariner and purchased a bezel assembly from WSO and crystals from both WSO and Clarks. Here's the measurements I took: WSO Crystal 25-127 30.25mm OD 28.1mm ID 27.8mm ID 1mm thick sidewall (step inside) 6.4mm tall 1.8x mag Clark’s Crystal 25-127 30.4mm OD 28.05mm ID 1.1mm thick sidewall 5.8mm tall 2.5x mag JKF Crytal 25-127 30.30mm OD 28.00mm ID 1.1mm thick sidewall 5.6mm tall 2.5x mag WSO Retaining Ring 30.2mm ID JKF Retaining Ring 30.26mm (sorry, I forgot to measure the rehaute) I understand none of these sources have rigorous QC so my dimensions could be off from what you get. In the end I used the Clarks crystal with the WSO bezel assembly. The Clarks crystal fit comfortably onto the rehaute but not securely (it didn't take much of any force to get it on). However, in sliding the retaining ring over the crystal everything came together very tightly (I could barely get the ring on). In the end I'm pleased to have a watch with friction keeping it together in lieu of glue and a prayer. Lesson learned is to order parts from multiple sources when replacing things - nothing is "gen spec". Crystals from left to right, Clarks (with WSO bezel assembly), JKF (with JKF bezel assembly), and WSO. Share this post Link to post Share on other sites
Daywatch 4 Posted July 19, 2018 Informative, nicely done with the measurements - and thanks for the comparison pics. Wear it well. Share this post Link to post Share on other sites
Lamuken 0 Posted August 23, 2018 Where did you get the parts for your jkf 1680? I would like to order them too? kind regrads Lamuken Share this post Link to post Share on other sites
Automotiveromance 1 Posted August 23, 2018 27 minutes ago, Lamuken said: Where did you get the parts for your jkf 1680? I would like to order them too? kind regrads Lamuken WSO and Clark’s.... Share this post Link to post Share on other sites
bobandshawn 5 Posted August 23, 2018 Nice write up - thanks! I recently found that the Clark's generally fit a little more snugly than the WSO, for whatever reason... B Share this post Link to post Share on other sites
J!m 289 Posted August 23, 2018 Clark's are the best alternative to old stock gen crystals. And, I prefer them to Rolex service crystals. Fit is "loose" because the case dimension is not correct. And yes, those retainer rings should be Wicked F~~~ing Tight! That's why I made a solid aluminum die to press them on... WSO has a good (not great) bezel assembly. I have found it best to order three assemblies from WSO and mix-n-match parts to get the right fit and function due to their tolerances in manufacturing. Note that gen retainers and gen bezels also vary rather widely, and Rolex made a tool to "adjust" bezels for proper function. Basically it's a bezel crusher that shrinks the diameter a bit. Here's an older picture of a new old stock 25-127 crystal on my Mk. I white dial (1973) 1680: (I can't find a good side view shot) Share this post Link to post Share on other sites
