Vintage Cal 861 Speedmaster Power Reserve

@Archer made it clear a 48+ hour reserve from full wind should be expected even on the older watch discussed here:
https://omegaforums.net/threads/as-...-moon-speedmaster-145-022.85626/#post-1104258

On my 145.022-69 I'm seeing more like 45-46 hours from full wind following a service which included a new mainspring. Had been at 43+ hrs reserve pre-service. The watchmaker said "older watches won't have the reserve of a newer one" but not sure I can accept given Al's comment.

Two questions:
1) Is there ever a legitimate reason a <48 hour reserve would be expected on a 49 year old cal 861 Speedy following a service?
2) If "no", how to tell the watchmaker he is wrong? I want to respectfully encourage correction to any missed service and maintain a relationship (maybe 😒). Other than power reserve the watch came back running OK. Actually it had been running OK before but given 8+ yrs since last service I'd hoped a new mainspring and cleaning would get me to 48+ hour spec.

I lack the expertise to credibly claim he might have missed something or describe what it might be. Also lack any desire to wear something out early by regular use.

Thanks and appreciate any guidance. Sorry if pecking about a non-issue.

[Gratuitous picture of sharp and now-correct pre-moon case back on subject watch]
https://omegaforums.net/threads/speedmaster-pro-145-022-dating-and-originality.88103/#post-1263845

45 hours is very good. Don't worry.

If you are not getting the full 48 hours after service, to me that indicates there is a problem of some kind (in other words I don't consider 45 hours to be very good, or even acceptable). You mentioned that the service included a new mainspring, but was that a genuine Omega mainspring? The length of the mainspring will to a large degree determine how long the watch runs, so if the spring wasn't an Omega spring and was some generic substitute, it's possible that the spring could be shorter. Length is the most flexible dimension when substituting mainsprings.

If it was an Omega mainspring, then the next thing is replacement or repair of worn parts. The most common repair I do to these is bushing the barrel arbor hole in the wheel train and barrel bridge. This hole gets worn oblong, causing the barrel to tip inside the watch, reducing the power being delivered by the mainspring, and this will affect the running time.

Here's an example - you can on the underside of this bridge that the ratchet wheel has been rubbing on the bridge from the barrel being tipped, creating a shiny spot:



Corresponding circular mark on the ratchet wheel:



Worn hole in the bridge after the parts were cleaned:



Bridge with bushing fitted:



In all the hundreds of these that I've serviced, I've never had one come in with a bushing already fitted here, so it would seem not too many watchmakers are fixing these. They could be replacing the bridges, but this would add several hundred dollars to the cost of the service, so my guess is most are just leaving them as they are, or are not even aware that this needs to be checked.

I do get 861's in that don't require this fix, but I would say at least 50% of them do need it. In fact I've made this repair on 1861's already, so this is a common wear spot on these watches. So mainspring would be my first guess, then failing to repair the worn hole in the bridge (this will affect balance amplitude as well), and then of course there are other possible worn parts.

Cheers, Al

Thanks all.

Padders, I believe he indicated Omega spring was used but I'll clarify. CW21 on his card but no Omega certification mentioned.

Al, my special thanks for the usual mind-blowing detail. Your expectation of full capacity and ability to achieve it points out the extra level of skill you bring to the table vs. my local options. I probably should have taken that shipping insurance risk and sent to you in the first place.

Barring a favorable response from watchmaker or a reply of "don't wind/use!" I'll live with 46 hour reserve until next service. Plenty for my needs. Watch is used lightly and not my daily.

I fully understand your point, but for me it's about doing the job right or not. Many people will accept sub-par work based on what I see on forums.