UR-100 series

The UR-100 SpaceTime and its distance scales

The UR-100 SpaceTime launched in September 2019. Three satellites carry the hour numerals, and the active one travels along the minute track, with a red-tipped pointer showing the minutes. When the minute pointer passes 60, it moves beneath the dial structures, and the next satellite takes over the hour.

The two scales are the family's signature idea. One scale, around 10 o'clock, shows the distance covered in 20 minutes by Earth's rotation, measured at the equator, which Urwerk gives as 555 km. The other, around 2 o'clock, shows the distance Earth covers in its orbit around the Sun in the same time, which Urwerk gives as 35,740 km. Urwerk states that neither scale measures your location or your personal travel.

The case of the original is 41 mm wide, 49.7 mm long and 14 mm thick, with a water resistance of 30 meters. The length includes the lugs, so check the figures against your wrist before you buy. The brand presents the UR-100 as mechanical theatre rather than a utility watch, and the size reflects that intention.

The UR 12.01 and UR 12.02 calibers

The original UR-100 uses the UR 12.01, a self-winding caliber running at 4 Hz with 39 jewels and a 48-hour power reserve. The UR-100V Iron, launched on November 11, 2020, uses the UR 12.02 with 40 jewels and the same 48-hour reserve. Its rotor is governed by the Windfänger, which is a regulator for the winding rotor rather than a timekeeping element.

A service on either caliber covers the satellite carriage, the rotor and its regulation, and the gear train. Because the regulator is part of the winding system, a shop that treats it as a timing component will misunderstand the watch. Ask how the rotor is tested after reassembly, and whether the shop will show you the winding behavior before the watch goes back in its case.

Specialized calibers can be slow to source, so ask before the watch leaves your hands. Find out whether the shop can obtain the part you need and whether URWERK has the technical documentation the job calls for. A quick answer to that question can save months.

What to check before buying a pre-owned UR-100

Start with the reference, the caliber and the serial number, and compare them with the papers. Check the Earth scales for clean, even printing, and check the satellites for smooth motion. A satellite that catches on its track or stops short is a sign of a fault, and so ask for a clear explanation before you agree.

Ask whether the watch has been serviced by URWERK or by an independent, and ask for the invoices. A satellite display that has been reassembled by someone without the right tools can show misalignment at the hour change, so test the watch through an hour change before you pay. Ask the seller to let you watch the transition, or arrange a second inspection.

The strap and buckle are the easiest parts to replace, but they affect the look of the watch. Ask whether the original strap and buckle are included, and whether the box and papers match the watch. Missing items are not a deal breaker on their own, but they should be reflected in the agreed terms.

Care and wear

Keep the satellites clean and free of dust, because grit on a track can slow a satellite or stop it altogether. Avoid knocks to the dial, which can shift a satellite out of alignment and take a service to correct. Have the seals tested at the interval the brand or shop recommends, and rinse the watch after salt water if it is rated for water use.

Expect the display to add to the labor on any service. The satellite carriage and gear train are more involved than a standard automatic, so ask for a breakdown of the estimate. If the first look suggests a simple job, be prepared for the estimate to change once the watch is open, and ask the shop to tell you before it does more work.

Keep every service record, including the date, the shop and what was done to the display. A future buyer or a new watchmaker will ask for the history, and a clear record makes that conversation easier and makes the watch easier to sell.

What to check on a UR-100 series

• Proof that the shop has worked on satellite-hour displays
• A test that runs the satellites through an hour change
• A clear statement of which parts were replaced, and whether they were genuine
• Written service history that covers the display and the rotor

Common questions