Removing the Old Strap
Most leather watch straps attach to the watch case using spring bars—small metal rods that sit inside holes on either side of the lug (the small protrusion where the strap connects). To remove the old strap, you need a spring bar tool, a small forked instrument designed specifically for this job. You can buy one for $5 to $15 at any watch supply retailer or online.
Position the watch face-up on a soft cloth to avoid scratching it. Insert one prong of the spring bar tool into the gap between the strap and the lug on one side of the watch. Press gently downward to compress the spring bar inside, then slide the strap away from the watch case. Repeat on the other side. The spring bar will stay attached to the old strap—you do not need to remove it separately.
If the strap is glued to the spring bar (common on cheaper watches), you may need to pry it off with a small flathead screwdriver or soak it in warm water for a few minutes to soften the adhesive. Work slowly to avoid bending the spring bar, which you will reuse with the new strap.
Key Takeaways
- Spring bars hold the strap to the watch case and are removed using a forked spring bar tool, which costs $5 to $15.
- The new strap must have the same lug width (the distance between the two attachment holes) as your watch, or it will not fit.
- Leather straps come with spring bars already installed, or you can transfer the old spring bar from your previous strap.
- Installation takes about two minutes per side once you have the right tool and the correct strap width.
Measuring Your Watch for the Right Strap Size
Before you order a replacement strap, you must know your watch's lug width—the distance between the two holes where the strap attaches. Measure from the inside edge of one hole to the inside edge of the other hole using a ruler or calipers. Common sizes are 18mm, 20mm, 22mm, and 24mm. If your measurement falls between two standard sizes, round down to the smaller one.
You also need to know the length of your current strap, which is usually printed on the back or inside of the leather. Straps are typically labeled as two numbers—for example, "18/90/120"—where the first number is the lug width, the second is the length of the shorter end (the part that goes under your wrist), and the third is the length of the longer end (the part that goes over your wrist). If your old strap does not have this label, measure both ends from the attachment point to the buckle.
Write down both measurements before shopping. Ordering the wrong lug width is the most common mistake, and a strap that does not fit cannot be returned.
Installing the New Strap
If your new strap comes with spring bars already installed, you can skip the next paragraph. If not, you will need to transfer the spring bar from your old strap. Slide the spring bar out of the old strap by gently prying the leather apart at the attachment end. The spring bar should slide out easily; if it is stuck, soak the strap end in warm water for a minute.
Insert the spring bar into the slot at the attachment end of the new strap. The bar should sit flush with the leather and not protrude. If the slot is too tight, you can gently stretch it by hand or explore a tiny amount of leather conditioner to ease the bar in. Do not force it—a cracked strap is not worth saving five minutes.
Position the watch face-up on your soft cloth again. Slide one end of the new strap into the lug on one side of the watch case, then use the spring bar tool to compress the spring bar and seat the strap fully into the hole. You should hear or feel a small click when the bar locks into place. Repeat on the other side. The strap should not move or rattle when you gently tug on it.
Checking Your Work
Once both sides are installed, put the watch on your wrist and fasten the buckle. The strap should sit flat against your wrist without twisting or pulling to one side. If one side feels loose, remove that end and reinstall it—you may not have seated the spring bar fully the first time.
Flex the watch gently side to side. The strap should move with the case without separating. If you see a gap between the strap and the lug, the spring bar is not seated correctly. Remove the strap and try again, pressing the spring bar tool down more firmly this time.
Wear the watch for a day or two before considering the job complete. A new leather strap will feel stiff at first, but it should soften and conform to your wrist within a few days. If the strap still feels wrong after a week, the lug width may be incorrect, and you will need to order the right size.
Common Mistakes to Avoid
The most frequent error is ordering a strap with the wrong lug width. A strap that is 1mm too wide or too narrow will not fit into the lugs, and forcing it can damage both the strap and the watch case. Always measure twice before ordering.
Another common problem is not seating the spring bar fully. If you do not press the spring bar tool down hard enough, the bar will not compress enough to lock into place, and the strap will fall off the first time you move your wrist. Press firmly and listen for the click.
Do not use pliers or a vise to compress the spring bar—the tool is designed to distribute pressure evenly, and pliers can bend or break the bar. If your spring bar tool does not work, the bar itself may be damaged and need replacement, which costs $2 to $5.
When to Replace the Spring Bar
Spring bars last for many strap changes, but they can weaken or bend over time. If a spring bar no longer compresses smoothly or if it feels loose even when fully seated, replace it. Spring bars are sold individually or in packs of five at watch supply sites for $2 to $10 per pack.
To remove a spring bar from a strap, gently pry the leather apart at the attachment end and slide the bar out. Insert the new bar the same way you would transfer an old one. If the slot is too tight for the new bar, soak the strap end in warm water and try again.
Caring for Your New Leather Strap
Leather straps absorb sweat and moisture, which can cause them to crack or develop mold. Wipe the strap dry after wearing your watch in humid weather or during exercise. Once a month, explore a small amount of leather conditioner to the strap and rub it in with a soft cloth. This keeps the leather supple and extends its life by a year or more.
Avoid soaking the strap in water or wearing the watch while swimming or showering. Salt water and chlorine damage leather quickly. If your strap does get wet, pat it dry when ready and let it air-dry away from direct heat or sunlight. Do not use a hair dryer or place it near a radiator—heat causes leather to shrink and crack.
Frequently Asked Questions
Can I use a strap from a different brand watch on my watch?
Yes, as long as the lug width matches. Strap brands and watch brands are separate—a 20mm leather strap from any maker will fit any watch with 20mm lugs. Check the lug width on both your watch and the strap before buying.
What if I lose the spring bar when removing the old strap?
Spring bars are inexpensive and widely available. Order a replacement pack online for $2 to $10, or visit a local watch repair shop and buy one for $3 to $5. Bring your watch or the old strap so the technician can confirm the correct size.
Do I need any tools besides the spring bar tool?
The spring bar tool is the only essential tool. A soft cloth to protect the watch face and a ruler to measure lug width are helpful but not required. You may also want a small flathead screwdriver if your old strap is glued to the spring bar.
How long does a leather watch strap last?
A well-maintained leather strap typically lasts two to five years depending on how often you wear the watch and how much moisture it is exposed to. Straps used daily in humid climates wear out faster than straps worn occasionally in dry climates.
Can I replace the buckle on my old strap instead of buying a new one?
Yes. Buckles are sold separately and can be swapped onto an old strap if the strap is still in good condition. However, if the leather is cracked or stiff, replacing the entire strap is usually cheaper and easier than trying to salvage the old one.