themoo-12 0 Posted June 14, 2010 I've seen around the site the movements in daytonas can have issues can someone explain why and is there a particular style or seller that makes one with the least problems? Share this post Link to post Share on other sites
dingle 57 Posted June 14, 2010 I've seen around the site the movements in daytonas can have issues can someone explain why and is there a particular style or seller that makes one with the least problems? the 7750 movement is not really made for "seconds at 6" check with PWC or Mary for the "seconds at 9" version......for some reason I remember them being hard to get...... Share this post Link to post Share on other sites
Silverspeed 10 Posted June 14, 2010 That will be the daytona with the seconds @6. The repmakers use an A7750 movement for that which has the seconds at the 9 o'clock subdial. In order to move the seconds from 9 to 6 the repmakers used 12 extra gears to make this happen. This modification is highly unreliable because the seconds gear runs on a metal plate, without using a ruby or jewel and therefor this can cause great friction...and changes are very high the movement will stop running. One option is to use graphite on the seconds gear, that runs on the metal plate, to reduce the extra friction, but if this is not done properly the graphite can cause extra friction.... Better option is to choose the Daytona with the seconds at the 9 o'clock subdial, the movement for this is unmodified and very reliable. Or you can choose the Daytona with a Chinese 21J movement... Share this post Link to post Share on other sites
Member X 91 Posted June 14, 2010 The 7750 movement is a seconds at 9 movement. To move the seconds to the six o'clock position, a number of transfer gears are added. The extra weight and the drag they create as the move on the metal plate slowly kills the movement. There is apparently a new improved seconds at 6 movement that has lightened gears, and you can graphite treatment the metal plate (or even DLC it) so they have less friction, but all are less than ideal. Stick to a 'vintage' Daytona (seconds at 9) and you will be fine as there are no transfer gears EDIT: Too slow Share this post Link to post Share on other sites
themoo-12 0 Posted June 14, 2010 Damn that was fast! Daytona sec at 9 it is! Share this post Link to post Share on other sites
themoo-12 0 Posted June 14, 2010 Ok now Im seeing the ones with the sec @6 that have lighter gears anybody have experiences with the new style? Share this post Link to post Share on other sites
Silverspeed 10 Posted June 14, 2010 Ok now Im seeing the ones with the sec @6 that have lighter gears anybody have experiences with the new style? they seem to be slightly better, but the problem remains in the problematic modification Share this post Link to post Share on other sites
GC 4,554 Posted June 15, 2010 Ok now Im seeing the ones with the sec @6 that have lighter gears anybody have experiences with the new style? I do, my Daytona purchased from Robert/PWC has the lightened gears. I'm very happy with it. What the hell can I say, all the advice you will ever receive on the A7750 w/ sec @6 is negative, but if you want the Daytona to be as accurate to gen as possible you throw caution to the wind and take the risk with the movt. I did and would do it again! Or you decide on a SS version pre 2000, which used the El Primero movt which ran a sec @9. But even there you must look for the better movt which has the sub dial spacing correct as not all A7750 w sec @ 9 do. Share this post Link to post Share on other sites
OHMYGODITSAPANERAI 0 Posted June 15, 2010 I have had a seconds at 6 Daytona since they first came out (and I have a second gen with lighter gears) both are withing COSC specs and have been since regulated. Not a single issue. Share this post Link to post Share on other sites
Luthier 1 Posted June 15, 2010 is there a particular style or seller that makes one with the least problems? Sellers (dealers) don't make watches, they sell it. Share this post Link to post Share on other sites
themoo-12 0 Posted June 15, 2010 is there a particular style or seller that makes one with the least problems? Sellers (dealers) don't make watches, they sell it. I meant what dealer sells the most reliable Share this post Link to post Share on other sites
Luthier 1 Posted June 15, 2010 is there a particular style or seller that makes one with the least problems? Sellers (dealers) don't make watches, they sell it. I meant what dealer sells the most reliable All well known dealers buy watches from the same factories. Difference is - some of the dealers are dropshippers, mean they never see the watch, factory people ship it, and some dealers inspect every watch before shipping. Share this post Link to post Share on other sites