Excesive movement speeds up sub?!

[Hydrographer]

Hey guys and girls,
quick question for you. I have had my sub c for over 2 months now and it keeps perfect time, gaining less than a second per day.
However the other week I wore it whilst doing grid sprints to time my sprinting.
A couple of days later I was on TRF and checked my watch and it was about 40 seconds fast. No problem, its not like it really matters but it just seemed odd. Then the other day I wore the sub again for grid sprints and the same thing happend when i checked the time afterwards.
I wear the watch jogging all the time and this does not happen. It only seems to be when Im running around like an absolute maniac and the watch is being moved vigorously.
I would have thought that this would only have the effect of fully winding the watch, not serve to actually speed it up. Or, is the second hand actually jumping forward during the exercising?
Its no big deal really as I usually use a didgital watch for suck activities, when i remember to take it. I was just curious as to the cause.

Thanks for any info in advance.

Alan

[Tools]

Here's the physics Alan...

A mechanical watch is timed using a Balance Wheel that is attached to a hairspring. The hairspring helps it oscillate (swing back and forth) with precision. There are other players in the game, but we'll ignore them for this discussion.

Typically the balance wheel oscillates about 300 degrees (called amplitude), and this take a certain amount of time... If all things are balanced, your watch is exactly on "time".

When you swing your wrist you cause outside forces to act upon the Balance Wheel and hairspring, typically stopping it from making a complete 300 degree oscillation.. If the forces are great enough, the amplitude will be reduced significantly - perhaps closer to 200 degrees of swing...

It takes less "time" for the balance wheel to swing 200 degrees than it does for it to make it's normal 300 degree swing - therefore, your watch is ticking at a faster rate (it speeds up).

Because the mainspring is also a player, and the forces it imparts on the balance affect this amplitude too, make sure that your watch is fully wound before you start your exercises..... Your movements (external forces) will affect the amplitude less on a watch that is fully wound than on one that is not fully wound..

[SCD]

I wear different watches in rotation and when I do wear them I typically play tennis and/or do some other rigorous cardio. I've noticed most of my watches tend to run 2-3 seconds slower when I'm wearing them than when I'm not.

[MURRAY]

Originally Posted by Tools

Here's the physics Alan...

A mechanical watch is timed using a Balance Wheel that is attached to a hairspring. The hairspring helps it oscillate (swing back and forth) with precision. There are other players in the game, but we'll ignore them for this discussion.

Typically the balance wheel oscillates about 300 degrees (called amplitude), and this take a certain amount of time... If all things are balanced, your watch is exactly on "time".

When you swing your wrist you cause outside forces to act upon the Balance Wheel and hairspring, typically stopping it from making a complete 300 degree oscillation.. If the forces are great enough, the amplitude will be reduced significantly - perhaps closer to 200 degrees of swing...

It takes less "time" for the balance wheel to swing 200 degrees than it does for it to make it's normal 300 degree swing - therefore, your watch is ticking at a faster rate (it speeds up).

Because the mainspring is also a player, and the forces it imparts on the balance affect this amplitude too, make sure that your watch is fully wound before you start your exercises..... Your movements (external forces) will affect the amplitude less on a watch that is fully wound than on one that is not fully wound..

So Larry...my SD that at times has gotten to +20 sec in a day could conceivably be within a normal parameter? Where does -4/+6 come in then...watches that sit running in a safe or on a desk for their 44 hours?

I was going to ask in a thread what contributes to watches running fast...but luckily someone asked the same question....

[Tools]

Originally Posted by MURRAY

So Larry...my SD that at times has gotten to +20 sec in a day could conceivably be within a normal parameter? Where does -4/+6 come in then...watches that sit running in a safe or on a desk for their 44 hours?

I was going to ask in a thread what contributes to watches running fast...but luckily someone asked the same question....

-4/+6, the COSC testing standard is almost always misused. This value, which is actually a 10 second swing from a baseline, are parameters during the multi-position and temperature test that the bare movement undergoes once in it's lifetime at the COSC test center...

It demonstrates capability in a controlled testing environment, not reality.

[MURRAY]

MAN...you are fast!!

Thanks....Rick

[RRGHOST1]

Larry,that was brilliantly explained. Maybe we will stop getting posts now about "my watch is gaining 7 seconds a day,and it is outside the COSC limits, do i need to send it away to Rolex to get regulated".

[Lion]

What I like with TRF is the learning and education I receive when reading these threads!!!

[jessiethe3rd]

My brain thanks you.

[chestercopperpot]

Originally Posted by Lion

What I like with TRF is the learning and education I receive when reading these threads!!!

i agree...i'm addicted to this thing. i've learned so much about watches.

[wokafu]

Originally Posted by Tools

Here's the physics Alan...

A mechanical watch is timed using a Balance Wheel that is attached to a hairspring. The hairspring helps it oscillate (swing back and forth) with precision. There are other players in the game, but we'll ignore them for this discussion.

Typically the balance wheel oscillates about 300 degrees (called amplitude), and this take a certain amount of time... If all things are balanced, your watch is exactly on "time".

When you swing your wrist you cause outside forces to act upon the Balance Wheel and hairspring, typically stopping it from making a complete 300 degree oscillation.. If the forces are great enough, the amplitude will be reduced significantly - perhaps closer to 200 degrees of swing...



It takes less "time" for the balance wheel to swing 200 degrees than it does for it to make it's normal 300 degree swing - therefore, your watch is ticking at a faster rate (it speeds up).

Because the mainspring is also a player, and the forces it imparts on the balance affect this amplitude too, make sure that your watch is fully wound before you start your exercises..... Your movements (external forces) will affect the amplitude less on a watch that is fully wound than on one that is not fully wound..

Thanks for the detail info...

[Z-Sub]

Originally Posted by SCD

I wear different watches in rotation and when I do wear them I typically play tennis and/or do some other rigorous cardio. I've noticed most of my watches tend to run 2-3 seconds slower when I'm wearing them than when I'm not.

If your watch tends to run slow, and if you leave it sitting with it facing up, it will run faster. I believe most Rolex watches tend to run slightly faster in this position.

furthermore, I believe as the main spring unwinds more, the watch runs ever slightly faster due to the change in the amplitude mentioned by Larry.

A couple of my watches that run about -1 second slow do exactly what you described.

[Hydrographer]

Originally Posted by Tools

Here's the physics Alan...

A mechanical watch is timed using a Balance Wheel that is attached to a hairspring. The hairspring helps it oscillate (swing back and forth) with precision. There are other players in the game, but we'll ignore them for this discussion.

Typically the balance wheel oscillates about 300 degrees (called amplitude), and this take a certain amount of time... If all things are balanced, your watch is exactly on "time".

When you swing your wrist you cause outside forces to act upon the Balance Wheel and hairspring, typically stopping it from making a complete 300 degree oscillation.. If the forces are great enough, the amplitude will be reduced significantly - perhaps closer to 200 degrees of swing...

It takes less "time" for the balance wheel to swing 200 degrees than it does for it to make it's normal 300 degree swing - therefore, your watch is ticking at a faster rate (it speeds up).

Because the mainspring is also a player, and the forces it imparts on the balance affect this amplitude too, make sure that your watch is fully wound before you start your exercises..... Your movements (external forces) will affect the amplitude less on a watch that is fully wound than on one that is not fully wound..

Thanks so much Larry. I knew it had to be something to do with me running around tike a loon but was keen to know the physics behind it. You described it in a way I could get my head around.

[padi56]

Originally Posted by rolexplorer2

Larry,that was brilliantly explained. Maybe we will stop getting posts now about "my watch is gaining 7 seconds a day,and it is outside the COSC limits, do i need to send it away to Rolex to get regulated".

Now that one I would love to see, but don't count on in,the COSC test is a average of -4 to +6 seconds over a 24 hour period.And over the period of testing, the movement could be out 10 seconds in the first 10 days and still pass the test...

[Boadicea]

Originally Posted by Z-Sub

If your watch tends to run slow, and if you leave it sitting with it facing up, it will run faster. I believe most Rolex watches tend to run slightly faster in this position.

This is not true of modern movements, from what I can tell, temperature makes more of a diffference these days. I also have a sneaky feeling that the new Parachrom spring may be better with shock and magnetism, but it is worse with temperature (hence they don't mention it in their adverts).

My 36mm Exp1 is very stable but my daytona gains 4 seconds per day just from my body temp (ie: cold safe/winder it runs -3 and on the wrist it runs +1).

[Z-Sub]

I doubt that much variation came from your body temp. COSC tests covers different ranges of temperatures as well. My experience with Daytona differ that of yours. It's very stable in terms of timing accuracy but does run a second faster after I'm on elliptical machine for an hour. If i just wear it in office, I don't notice significant variations.