Is Amplitude Alone an Indicator of Need for Service?

[seattleal]

Actually, I am interested in the converse - is adequate amplitude sufficient to indicate a Rolex movement Does Not need service?

That is, if the amplitude is within tolerance on a 15xx movement is that alone enough to forgo service, or does the watch still need to be opened and examined to make that determination?

[007Sub]

Originally Posted by seattleal

Actually, I am interested in the converse - is adequate amplitude sufficient to indicate a Rolex movement Does Not need service?

That is, if the amplitude is within tolerance on a 15xx movement is that alone enough to forgo service, or does the watch still need to be opened and examined to make that determination?

Excellent question! To an extent I think it depends on who you ask. Apart from amplitude (which you want to observe in the flat/horizontal positions, you also want to inspect the vertical positions (crown left, crown down and crown up). After sales service tolerances for the 15XX calibers have a maximum acceptable delta (largest positional deviation) of 25 seconds. At 40 winds (full power) you should generally see an amp btw 250-280 in flats and no less than 200 in the verticals. If the movement is dipping below those numbers or has a larger delta than 25 or is difficult to wind, feels crunchy, makes excessive rotor noise when shaken then regardless of the numbers it might be prudent to service. The more regularly services are carried out the greater the longevity of the movement.

[Dirt]

Originally Posted by 007Sub

Excellent question! To an extent I think it depends on who you ask. Apart from amplitude (which you want to observe in the flat/horizontal positions, you also want to inspect the vertical positions (crown left, crown down and crown up). After sales service tolerances for the 15XX calibers have a maximum acceptable delta (largest positional deviation) of 25 seconds. At 40 winds (full power) you should generally see an amp btw 250-280 in flats and no less than 200 in the verticals. If the movement is dipping below those numbers or has a larger delta than 25 or is difficult to wind, feels crunchy, makes excessive rotor noise when shaken then regardless of the numbers it might be prudent to service. The more regularly services are carried out the greater the longevity of the movement.

This probably sums it up nicely

[watchmaker]

When taken in isolation, poor amplitude indicates a need for a service - however good amplitude does not necessarily indicate no-need for one.