Shock Resistance is a fairly recent term in the world of watches. As more and more people are leading active lifestyles, watch brands are going to great lengths to create timepieces that are resistant to damage when dropped or when subjected to stringent and constant motion
The balance wheel is one of the most critical parts of a mechanical watch. The balance and hairspring are the parts that regulate the watch and ensure that your watch is running on time. If a watch is dropped, it can damage the wheel’s delicate pivots and either cause your watch to stop or run inaccurately. In 1934, two Swiss engineers Georges Braunschweig and Fritz Marti invented the Incablocc shock protection system in order to relieve the balance wheel from such shock. Prior to this time, broken balance staffs were a common problem.



Supporting the balance wheel is no easy task. The pivots and jewel bearings are quite fragile and easily damaged. The Incablocc system uses a specially shaped spring (like a lyre) to allow the bearings to shift a little. By doing this, the pivots and bearings don’t have to bear the brunt of the force itself. After the shock, the spring guides the parts back to where they belong.
Other types of Shock springs




Shock springs are a great idea and most styles work as designed. The problem is they are made of brass and can break if not handled correctly. Also, since they are brass, if you drop one, they are just about impossible to find, since they are non magnetic. If an Incabloc spring needs to be replace, that is a project that is just about impossible to do. The springs are so thin and difficult to hold. that any repair or replacement will make any watchmaker earn their money!!
Wyler Inca Flex balance wheel
Back in the late 60’s the Wyler watch company took shock resistance one step further, when they invented the Inca Flex balance wheel. The balance was constructed in such a way that it also added to the shock resistant properties of the watch. A novel idea that never really caught on.

Vintage Pocket watch balance jewels
Older watches have balance jewels that offer no shock absorption to the balance wheel. Anyone that uses a vintage pocket watche, knows that a drop to a hard surface is going to end in a broken balance staff. Even if the staff does not break, it can bend slightly causing the watch to run erratically. So the invention of shock springs was a huge leap forward in making a watch more reliable in everyday use.

Some brands today also deal with the issue of shock resistance by using new materials for the balance and hairspring. This includes using synthetic jewels, silicon hairsprings, non-ferrous escape wheels, as well as adding inner and outer containers to the housing. Some brands have even developed all new case constructions with pressure absorbing elements.
Please keep in mind that there is no such thing as “Shock Proof”. I see Rolex watches come into my shop that have a broken balance staff. Even though they have great shock springs, if you drop it hard enough you can still break a staff.


21 Comments
Johnny
Thanks Mark. Another great informative article.
Michael Fisher
Another interesting article. Thanks!
Alex
Outstanding. Thank you for explaining things in layman terms. That is a great skill. You are to watches what Dr Julius Sumner Miller was to physics for me.
Joel
Very informative.
Thanks
John
Wow! Completely explained in layman’s terms! Thanks Mark
!
Mike Betlow
Very cool, I always thought Incabloc was referring to the case
Mark Morgan
Great story never gave it a thought.
Mark
Melvyn Schuman
Your article cleared up some questions about “shock proof” watches. Wonderful essay. Thank you, Mel
Salvatore lobosco
Great job mark, informative and simple terms
Patrick Bissell
Great article Mark and a really necessary reminder. You’ve fixed a pocket watch for me in the past. Thanks to you and the fact that I haven’t dropped it again, it works fine.
Terry Black
Always informative in understandable language. Keep it up, we’re always learning from you…
Bill P.
Great article. So what’s in a Rolex?
GregK
Good work Mark and very informative. Appreciate these knowledge papers.
Mie M
I enjoy these educational discussions about mechanical watches.
Very interesting.
Frank P.
Very interesting and informative article! Thanks Mark!
SEBASTIAN FERNANDEZ ELLERO
I`ve always wondered what the “shock resistance” was all about. Excellent explanation as always.
Thanks Mark.
Tom Gonzales
Thanks Mark, I am finding that I really love to read the information that you send. I am to the point that I can hardly wait until the next piece comes to me via email. I am a mechanical watch lover and have NEVER worn anything but mechanical watches. Just way cool little machines that provide a vital function. Thank You so much.
Tom
William H Shockley
Hey Mark, I’ve got a Wyler from the ’60’s. It’s a mechanical wind with an ETA 2370 and the Wyler Incaflex balance wheel mod. It’s a nice little watch for sure. I encourage your readers to check them out on Ebay. They are affordable and make a great work watch with some real vintage cred. Wyler dropped them off the Eiffel Tower and the Space needle as advertising stunts. The man was ahead of his time.
here’s a good internet read on them.
http://goldsmithwatchworks.com/APRIL-2014/WYLER/ALL%20ABOUT%20THE%20WYLER%20WATCH%20COMPANY%2039%20PICTURES.htm
Thanks for your article.
Bill
James Rizzo
Thanks Mark. Very informative. I have a wyler uncalled with a broken staff. Do you know where I can get one or have one made. Thanks jim
James Rizzo
Sorry sometimes the computer prints which a t it wants. Wyler incaflex. Jim
Petar
Exelent aricle. If possible would like to see difference between Kif and latest Rolex shock absorber claming 50% better then others?