Changing a watch strap takes about two minutes once you know the technique. The process involves compressing a small spring bar at each lug, sliding the old strap free, and snapping the new one in. At JackCoHenry, we walk every first-time client through it at the appointment — this guide covers the same steps for anyone doing it at home. Walk through it once carefully, and it becomes second nature.
What You'll Need
Essential:
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A spring bar tool — the forked end gives you control and reduces the risk of slipping.
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A soft surface to work on — a cloth or leather pad prevents scratches if a spring bar drops.
No spring bar tool? Alternatives:
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A SIM card ejector pin — thin enough for most lug gaps.
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A thin flathead screwdriver — wrap the tip with tape to avoid marking the case.
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A toothpick — works in a pinch on watches with wider lug gaps.
Removing the Old Strap
Step 1: Position the watch
Place your watch face-down on a soft cloth. You'll be working on the underside of the lugs, so having the dial protected and the case stable is important. Good light helps — the spring bar tips are small.
Step 2: Locate the spring bar
Look into the gap between the lug and the strap end. You'll see the spring bar — a thin metal pin with a recessed tip visible on each side inside the lug hole. The fork of your spring bar tool goes into this gap.
Step 3: Compress and release
Insert the forked tip of the tool between the lug and the strap edge, locating it against the spring bar tip. Push inward (toward the centre of the watch) to compress the spring bar. While holding it compressed, lever the strap end outward slightly — the spring bar tip will clear the lug hole and the strap will lift free on that side.
Step 4: Remove the spring bar
Once one end is free, tilt the strap to slide the spring bar out of the opposite lug hole. Keep a finger over the spring bar — it will pop out under tension and is easy to lose. Repeat for the other half of the strap (long piece and short piece each have their own spring bar).
Fitting the New Strap
Step 5: Load the spring bar
Slide the spring bar through the hole at the lug end of the new strap. Centre it so equal lengths of the bar extend from each side. Your JackCoHenry strap includes spring bars sized to match — use those rather than the ones from your old strap unless the diameter is confirmed to match.
Step 6: Seat one side first
Hold the strap in position under the lug. Push one end of the spring bar into its lug hole — you'll feel it click into the recess. Keep it held in place with light finger pressure. The bar should sit flush; if it feels loose, check it's seated in the hole rather than resting on the edge.
Step 7: Compress and seat the other side
Use the forked tip of the spring bar tool to compress the free end of the spring bar inward. With the bar compressed, align the strap under the lug and release — the spring bar should snap into its hole. You'll hear and feel a small click. Give the strap a firm tug to confirm it's secure on both sides.
Step 8: Repeat for the other half
Fit the short piece (the buckle half) using the same method. Once both halves are seated, flip the watch over, fasten the strap as you normally would, and check that it sits flat against the case with no gaps at the lugs.
Common Mistakes to Avoid
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Working on a hard surface. If a spring bar pops free and hits the table, it can ping across the room. Work on a cloth.
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Using a solid pin instead of a fork. A solid tip pushes the spring bar down instead of compressing it, which can scar the lug or the strap end.
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Not checking both sides are seated. A spring bar resting on the lug edge rather than in the hole will work loose with wear. Always tug-test after fitting.
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Reusing a bent or short spring bar. If your old spring bar looks compressed or shorter than the lug width, replace it. A weak spring bar is a strap separation waiting to happen.
Rolex tip: Rolex uses sharp lug edges on some references (Submariner, GMT-Master II). When fitting a straight-end strap, place a thin strip of tape along the case edge where the strap contacts the lug — it protects the leather from being nicked during wear.
Frequently Asked Questions
Q. Do I need a spring bar tool?
Not strictly — a SIM ejector pin or thin flathead screwdriver works. But a spring bar tool is much easier to control and reduces the risk of scratching the case. If you swap straps regularly, it's worth having one.
Q. How do I know which spring bar size to use?
Spring bar length should match your lug width (e.g. 20mm lugs need a 20mm spring bar). Diameter is usually 1.5mm for dress watches and 1.8mm for sports watches. Your JackCoHenry strap comes with correctly sized spring bars — use those.
Q. My spring bar flew out — how do I find it?
Work on a cloth next time. If it's gone, spring bars are inexpensive and sold in packs. Make sure you buy the correct length and diameter. Using the wrong size is a common cause of strap failures.
Q. The new strap gaps at the lugs — what's wrong?
Either the lug width doesn't match (you've fitted a 20mm strap to a 22mm lug, for example), or you have curved lugs that need a curved-end strap. Check your watch's lug width before ordering.
Q. Can I change the strap on any watch?
Most watches with standard parallel lugs and spring bars can be swapped easily. Integrated strap systems (Audemars Piguet Royal Oak, Cartier Santos, and similar) are not compatible with standard aftermarket straps.
Q. How often should I change my strap?
There's no rule — change it when the leather shows significant wear, when it no longer holds its shape, or simply when you want a different look. A well-made leather strap will last 1–3 years with regular use.
Related Articles
→ Fit Guide — will this strap fit my watch?