Help - How to look after a 7750 (chrono movement)

[Rclough]

Good people of RWG, I have recently been told that the movement in my IWC Top Gun (Asian Valjoux 7750) is knackered and needs replacing. Problems began when the watch stopped (for no reason) while on the watch winder; to overcome this I started manually handwinding the movement … This worked OK for a few weeks, until one day (whilst hand winding) the noise and feeling inside (sorry for lack of technical terminology) went from a pleasant smooth feel, to a nasty internal ‘crunching’. At this point it was game over … into the repairers, where I was handed the bad news. The joys of rep ownership eh? Boo!

So, I’ve bitten the bullet, and decided to go ahead with a brand new movement, fully serviced and pressure tested. What I now need to know is when the watch is returned to me, how I can prevent a similar situation occurring in the future?

I have heard all sorts of stuff & frankly, I don’t know what to believe (e.g. don’t change the day / date between the hours of 10-2; avoid sudden ‘jerky’ wrist movements (ha, ha!); don’t use the chrono function (which seems weird to me, as surely that’s one of the joys of chrono ownership!) etc etc.)

In short, (and I have read previous posts on the subject) … What’s the score when it comes to 7750’s? Should they be handled like spider webs or are they as robust as regular (non chrono movements)? Lets set the record straight once and for all. Look forward to hearing your comments and as always, many thanks in advance. rclough

[FxrAndy]

A propperly serviced movement

Dont change the date with the hands between 9pm and 3 am as this is when the date change mech is engaged (this is the same for swiss)

Dont hand wind as the week point is the gearing and you stand a chance of snapping teeth off gears (swiss gears are better)

Nothing wrong with using the chrono if it is working, but i would recomend (on asian ones) that if you are timing some thing and you stop the chrono with the second hand at say 40 seconds, then restart it once you have read the time that you want to record, then restart the chrono and let the seconds hand get back to the area of 60 seconds, this has nothing to do with the movement but the quality of the asian hands,

When you reset the chrono a hammer hits a heart shaped cam and the long seconds hand accelerates from where it is to the zero position in about 100th of the second, the tourque that this imparts to the tube where the seconds hand is joined with the movement is the week point and can cause the hand to move on the tube and then it wont reset to zero.

My question is where are you getting the movement from, if it is from China then how will you know it is serviced ect, or is it from your watch maker who will give some sort of guarentee?

[Rclough]

Thank you fxrAndy for your comprehensive response; I've given the watch to Tom Exton who posted here recently. He has a watchmaker (London based) that he believes in, and it is him that is doing the work for me; so far so good; had great comms from Tom and am looking forward to getting the watch returned to me soon; will post a full summary when the work is done. In the meantime and once again, thanks for sharing your knowledge; have a great weekend everyone and long live RWG. Rclough

[FxrAndy]

Any time,

remember the RWG is the best horolgical site on the internet IMHO, but only peoples support keeps it going.

[freddy333]

Search out Ziggy's A7750 reviews.

[importr]

IMO, if you intend to keep the IWC for a long time, go Swiss. Well worth it. Not only it is built better, and with better materials, it can take can a few knocks.

I've never had an ETA 7750 fail on me, and just the other day i rec'd a new ETA which i accidentally dropped when unpacking. It bounced off a wall radiator and then onto the floor. As you can imagine I was bricking myself thinking I'd just snapped a hand post or two etc., but on close inspection: no damage! I even fitted hands onto it to test the regulation & functions: A-OK!

[maxman]

I've had around 20 reps with the a7750 movement...not one issue so far. My Pam 250 was running a little slow so I had it serviced. My experence has been very good with this movement. Follow the advice above and Im sure you will feel the same about this fine reliable movement.

Good luck.

Mike

[Rclough]

Thanks for all your input. I have checked out The Zigmeister's posts (cheers Freddy333), and I feel much better informed. Will let you know how I get on with Tom Exton's watchmaker in due course. All the best - rclough