6R35 accuracy

I've had one since October, been slow 10-15 sec/day the whole time. I read of some people having theirs settling in. If I wear it multiple days in a row, I've found that storing it in the watch box dial down at night brings it back closer to real time, so it averages ok. I wish it ran fast too, might get it regulated.

My SPB143 also ran about 10 or 11 spd slow out of the box, so I regulated it myself. It took a couple tries to get it zeroed in, but now it runs almost spot on 0 to +/- 1 spd most days with little variation. This has enhanced my appreciation of it a lot.

In my case I have found with multiple movements that they finally take a couple of weeks to settle and move to a mora stable performance in which moment I usually decide to keep them that way or regulate. But this experience has been with the 6R15, Miyota's 90XX series and ETA 2824 and similar.

The 6R35 is the most inconsistently inconsistent movement I have ever encountered.

If you get a good one, they can be bang-on. As others have said, they seem to take a few days of constant running to settle in.

If you get a bad one they can be all over the place, timing-wise.

The accuracy of the movement seems to depend on the amount of wind, the position of the watch, how long it has been running and probably a dozen other small factors. It can be +1sec one day, then -17sec the next.

I took mine to a local watchmaker for regulation. The watch was 3 weeks old at this point. They had it for 2 weeks, trying to regulate it. In the end they handed it back (free of charge, fair play to them) admitting defeat. They said that nothing short of a full rebuild could get the movement to regulate.

It's the only movement I think would actively put me off buying a watch.

I usually let my Seiko movements settle for a month or so before regulating it. I bought my SPB239 in December, was running like -10 seconds but just let it break in for a while and it settled to -5 seconds a day. Got it regulated at the start of February to +3 seconds dial up, and been in continuous use. Only changed the date last month and never set the time since. Currently wearing the watch and it has only gained 6 seconds since.

Seiko movements positional variance is varied so when it on the wrist, it corrects itself. I usually take the accuracy for four positions dial face up, dial face down, 12 down and 6 up to set the final rate with the dial face down.

Glad it turned out good for you!

Guess I’ll break it in before regulating it if necessary. I really love the Seiko design but the movement is such a bummer.

A quick update. I have just taken it back from service. Watch runs approx +6 to +8 secs right now after a night dial up. I’ll monitor and hope it’s sorted out now.

I had to have my SPB143 sent in twice to Seiko. The first time it was running between -13.9 to -50.8 depending on its position. After getting it back the first time, it ran great for a few days and was even tested by the jeweler prior to handing off back to me. Then something caused it to run greater than a minute off/day. After sending it back in (all under warranty) they did a complete teardown and rebuild of the movement and a full regulation. Now it is running +/- 1-2 seconds a day and have not had any significant deviations from this for around 3-4 weeks.

That’s good to hear! Mine was just regulated and it’s running approx -2.5 secs a day. Works alright to me given that I do swap it out with other watches these days.

Is there a position in which the 6R35 movement is supposed to run faster? I've noticed on my SPB153 that it runs -10s when I wear it actively, but it seems to gain a bit of time when resting dial up. Haven't tried other positions, though.