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> Why is the ...
Why is the 8541b ....
June 26, 2001
8 Discussions and Comments
Member since March 26, 2001
considered to be a one of IWC's "best" movements?
I've read many expert's praise for this movement but would
appreciate a non-expert's understanding of its unique features
that has resulted in this praise.
Also, has IWC considered a re-introduction of this movement?
June 27, 2001
The specific member who posted this comment can not be uniquely identified by username.
The basic IWC automatic caliber, of which the Cal. 8541B, is the last descendant has proven itself as an excellent movement. It originated as the Cal. 85 in 1950, evolved to the Cal. 852, then 853 and then the 854 (and corresponding movements with dates, denoted by a 1 at the end –such as Cal. 8541). Given that it was in production for over 40 years, and enhanced in each iteration, it has proven itself as durable, accurate and incidentally easy to service. Above all else, its winding system, developed by IWC’s famous technical director, Albert Pellaton, has achieved great acclaim.
De Carle, one expert who wrote “Complicated Watches and Their Repair”, said about the winding mechanism “It is a simple and most ingenious system, well constructed and beautifully finished”. Brunner and Pfeiffer-Belli, in their book “Wristwatches Armbanduhren Montres-bracelets” call the Cal. 853 “one of the best automatic movements ever built in Switzerland”.
In my view it is not the most beautiful movement, nor is it decoratively finished. It also is relatively thick at 5.90 mm (for the 8541 with date). It is not a high beat movement (at 19,800 bph). But it works very well. My examples wind so easily that if I just pick a Cal. 8541 watch up and then put it down, it starts in beat. Mine are all uncannily accurate –chronometer accuracy after 30 or 40 years. Mine never seem to skip a beat, never seem to knock (over-bank), and just keeps accurate time.
In a sense, all wristwatch movements use the same basic design principles: the Swiss lever escapement has been around for a long time. Subtleties of finishing are sometimes cosmetic. But the story on the 8541B is a simple one: it is a well-designed movement that has stood the test of time. In each iteration from 85 to 852 to 853 to 854 and finally to the 8541B IWC has enhanced the movement. Some changes were major –like the 853 has an improved barrel—and actually the 8541B is arguably a minor improvement over the 8541 (if I recall there was a modification to the regulator).
The one particularly unique feature, and perhaps the distinguishing feature of any automatic, is the winding system. Contrary to most other watch designs, in the "Pellaton” winding system (as used in the Cal. 85xx’s and now in the new Calibre 5000) the movements of the rotor are not transmitted to a wheel train via a gear system but instead move a heart-shaped cam to activate a rocker. Two ruby rollers on the rocker ride on the cam, and the other end of the cam uses a pair of pawls to transmit the kinetic energy to a ratchet wheel with helical teeth, and from there to the winding wheels and barrel. The above image shows the unique and praised winding system, now in the Cal. 5000.
The winding system is noted for its efficiency, durability and ease of maintenance. The rotor winds bi-directionally and there is a sprung rotor mount to protect the rotor bearing from damage due to the mass of the rotor. Essentially, this part of the winding mechanism is shock resistant (the other parts of the winding system are not protected by this design, nor do they need it). Relatively few other winding systems are shock resistant.
IWC has no plans to resurrect the past, but to my knowledge might use the design elements in the future. Other than finding a vintage piece, for the time being you might need to look at the new Calibre 5000 in the Portugieser 2000.