Seiko mainsprings? What's the consensus?

[Simeon]

In my lineup for service, I have a Seiko 7009A to do. The last Seiko 700x that I did (it was a 7006A), I just cleaned, greased and reused the mainspring. I got reasonable amplitude for a Seiko of 260 degrees. The 7009A however has consistently low amplitude (max of about 200 but typically about 180) which seems to depend upon the state of wind in the watch. The watch itself actually keeps excellent time when worn with literally no difference between DU and DD positions and little variance on the vertical positions on the timegrapher. If it wasn't for the low amplitude, I wouldn't be considering servicing the watch. 

Anyway, my question is this: I have read in a few places that I should always use the factory Seiko mainsprings because the new GR Swiss replacements which are dimensionally the same have a thinner, weaker bridle. Is this still the consensus?

I am not convinced the mainspring in this 7009A watch is good to reuse given its low amplitude and so I might be looking for a mainspring from a donor (potluck) or a NOS one (also potluck).

 

Has anybody got good results with the GR mainspring?

[watchweasol]

Hi   I have used a few and had no bother. We are always hung up on amplitude, if the watch works as it should and keeps good time as is I would just service the watch as normal but if when removing the mainspring it looks set or damaged it will require changing . If ok reuse.

[Waggy]

1 hour ago, Simeon said:

Has anybody got good results with the GR mainspring?

I have used generic mainsprings in a few Seiko watches and to be honest I don't see any a smoking gun when looking at  amplitude which seems the same as using the Seiko original. However, there are sooooo many factors that can influence amplitude it is hard to blame the mainspring, or conclude that it makes no difference (as something else may be the limiting factor, so the effect [good or bad] of the spring is masked). I will continue to use the generic springs as I have yet to see a problem with them. Probably not the definitive answer you were looking for, but it is difficult to pin down one component in a multi-component mechanism.

[Neverenoughwatches]

6 hours ago, watchweasol said:

Hi   I have used a few and had no bother. We are always hung up on amplitude, if the watch works as it should and keeps good time as is I would just service the watch as normal but if when removing the mainspring it looks set or damaged it will require changing . If ok reuse.

Personally i think too much emphasis is placed on getting high amplitude. Dependency of it varies between different watches. An example i have is a 60 year old Raketa that produces around 220 -240 ° at full wind 180-200° after 24 hours depending on watch position. Keeps very good time, a minute or so deviation per week, winding once per day and stays within one hour of the specified power reserve when i don't wind it.

[JohnR725]

4 hours ago, Neverenoughwatches said:

Personally i think too much emphasis is placed on getting high amplitude

Oh dear this won't do it all? We're going to have to find you a different discussion group to be on because this is the group that 300° or death is the only acceptable answer.

Yes of course this is always my amusement the watch companies if they published specifications they don't care about amplitude either they only care about timekeeping what a weird concept. Then if they even publish their amplitude specifications it depends upon the company for instance Seiko does not although they now publish a lift angle maybe someday they'll give us an amplitude. But the other companies only care about amplitude at 24 hours and of course the watch still has to keep time. Typically it's 200° thoughts some of the watches will go West I've seen some ETA watches at 190° and Omega it depends on the caliber will go down to 160°.

So yes until customers have timing machines the watch companies only care about timekeeping because that's all the consumer cares about. Unless a course Huron discussion group and anything less than 300 considered yourself a failure and maybe should take up another hobby.