Asian 7750: minute doesnt begin to move for 1 minute after being set...

[Guest carlsbadrolex]

Two days ago I realized when trying to test the accuracy of my 6265 Daytona something very odd is happening. I pull the stem to stop the watch with the sub second at 12. I set the watch to the next minute... then when the computer clock changes, I push the crown back in and the sub second begins to move... BUT, the minute hand will not begin to move until EXACTLY one minute later. Then it will move as it should. THUS, my watch is now exactly one minute slow.

To make sure I was correct, I repeated this process, but set the watch TWO MINUTES ahead. I watched the sub seconds tick through the first minute with no movement of the minute hand. THEN as soon as the sub second hit 12 again, the minute hand begins moving. And as the sub second hits 12 again, the minute hand has moved to the next minute and the watch is accurate.

Any suggestions? I had never noticed this before on this particular watch...

[Rolexman]

All my Asian 7750s do the exact same... weird I know. I just set the time 1 minute in advance bepore pushing the crown.

Edited July 17, 2007 by Rolexman

[richard lawton]

I have several Swiss 7750s that do exactly the same also,

but no problem with the movement or accuracy.

Richard

[RWG Technical]

Quite normal on the A7750, and many models with offset cannon pins, including gen's...

The offset cannon pin feeds a minute gear, which drives both the center cannon pinion and hour wheels (on which the hands are attached). The extra gear accounts for this issue, as well as there being two more gears between the stem, and the center cannon pinion...

All this adds up to slack between the gear teeth (5 gears in total from the driving cannon pin, to the stem gear where you set the time).

It can't be fixed, just set the time one minute ahead.

RG

[Guest carlsbadrolex]

Thanks alot guys!!! Amazingly enough the watch was +/-10 sec. and after a couple days of adjusting, it is =/-5. Which is plenty acceptable!

[Rolexman]

Great Job!... welcome to the Chronometer club

[Pugwash]

It can't be fixed, just set the time one minute ahead.

... or set the time widdershins (counter-clockwise). Because of the way the 7750 (this only works on a 7750) is made, the slack can be taken up counter-clockwise but not clockwise.