Longines Ultra-Chron watch servicing

This watch is a vintage Longines Ultra-Chron model dating from the 1970s. It has a gold plated case, a cross-hair dial and a date at 3 o’clock. The Ultra-Chron is an automatic high-beat watch. This means the watch effectively ticks more per second than many other mechanical watches. The old standard for mechanical watches is to run at 18,000 BPH. This is 2.5Hz, or 5 beats per second. The Ultra-Chron doubles this – running at 36,000BPH – 5Hz or 10 beats per second. This – in theory – makes it easier for the watch to attain an excellent level of timekeeping accuracy. It also makes the second hand run more smoothly if you closely examine it.

There are however disadvantages to high beat movements, The fact the watch is beating so fast means the need for regular servicing is much more important, as parts will wear out considerably quicker. Indeed, there’s still a conversation ongoing about which standard is best, with the four main standards we see being 18,000, 21,600, 28,800 and 36,000 BPH.

On inspection of this particular watch, the amplitude of the balance was found to be very poor, This is often a sign a watch is in need of a thorough service. We also noted the date change was not working properly, so this required some attention.

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To service the movement it is completely disassembled and pre-cleaned, with each part inspected. The disassembled movement is then run through our specialist watch movement cleaning machine, while the case was cleaned in an ultrasonic cleaner. After an initial clean everything is checked before it then goes through a final cleaning cycle.

The movement powering this watch is a Longines calibre 461. This is a 17 jewel automatic movement of good quality. Inspection of the date change components found a replacement spring had previously been fitted, and this was too weak to provide the correct, snappy date change required. We were able to source and fit a replacement and this resolved the problem.

After all the movement parts are completely clean, it’s time to begin reassembly and oiling. The movement is rebuilt in stages, with everything checked to ensure it is just as it should be before moving on to the next stage. Once the movement is back together, the dial and hands are then refitted before the watch is cased up.

Do you have a Longines, or in fact any vintage watch in need of repair? Get in contact with us to see how we can help. We are able to repair almost any watch and we offer a comprehensive watch repair service. We cater to clients all around the UK thanks to our fully insured freepost watch repairs service. You can also bring watches in to our showrooms based in Lewes and Uckfield, Sussex. As Business Partners of the British Horological Institute and a Feefo Platinum Trusted Service Award accredited business, you can be confident when dealing with us.

Yours sincerely

David Clark DGA PJDip PJGemDip CertGA

Managing Director

W.E. Clark & Son Limited