How to Change a Watch Strap

To change a watch strap, lay the watch face down on a soft cloth, release the spring bar at one end of the old strap, lift that half out from between the lugs, and repeat on the other side. Then fit the new strap the same way in reverse, checking that each spring bar is seated fully in its lug holes. With quick-release spring bars this is usually done by hand, without tools.

Every Cernir strap comes with two quick-release spring bars already fitted, so most of this guide covers that method. If your current strap uses standard spring bars, there is a short section on removing them with a spring bar tool, plus a few habits that help keep the case free of scratches.

Before you start

Check your lug width first

Before you order or fit anything, confirm the lug width: the distance between the inside faces of the two lugs where the strap sits, measured in millimetres. A strap that is too narrow leaves gaps at the sides; one that is too wide will not sit between the lugs. The spring bar also has to match: a bar that is too short will not reach both lug holes, and one that is too long will not go in.

The quickest route is the watch maker's specification. If you cannot find it, measure across the gap with a ruler or calliper once the old strap is off. Our guide to finding your lug width walks through both methods. Cernir straps can be ordered in lug widths from 10 to 30mm, and the watch strap sizing guide covers buckle width and length if you are choosing a new strap at the same time.

What you need

• A soft cloth or towel to work on, so the crystal and case rest on something gentle.
• For standard spring bars only: a spring bar tool with a forked tip.
• Optional: low-tack masking tape to cover the inner faces of the lugs if you are using a tool.
• A clear, well-lit table. Spring bars are small and can jump if they slip, so avoid working over a carpet or an open drawer.

Step by step: quick-release spring bars

A quick-release spring bar has a small lever on it. Moving the lever compresses the spring and draws one end of the bar back out of its lug hole, so the strap comes free without a tool near the case.

1. Lay the watch face down on your cloth with the strap opened out flat.
2. Find the small lever on the spring bar, close to where the strap meets the lug. On most quick-release straps it sits on the underside, the side that faces your wrist.
3. Slide the lever with your thumb in the direction that pulls the pin back from the lug hole. On Cernir straps the lever is placed so a right-handed person can slide it comfortably with the thumb. If it does not move easily, check you are pushing it the right way rather than pressing harder.
4. Tilt that end of the strap out from between the lugs while holding the lever, then lift the other end of the bar out of its hole.
5. Repeat on the other half of the strap.
6. Fit the new strap: place the fixed end of the spring bar into one lug hole, hold the lever back, line the pin up with the opposite hole and let go.
7. Check that it is seated. Give the strap a firm tug and try to move the bar sideways. It should not shift or come out. If it does, refit it.
8. Check the orientation. Typically the half with the buckle goes at 12 o'clock and the half with the holes at 6 o'clock.

If a spring bar will not go in, or the strap will not sit between the lugs, stop. Do not force it. Check that the lug width and the spring bar length match your watch before trying again.

We place the quick-release lever for a right-handed wearer to slide with the thumb, as this short clip explains.

Standard spring bars with a spring bar tool

Many straps supplied with watches use plain spring bars with no lever. These have a small shoulder near each end, and you compress them with the forked tip of a spring bar tool.

1. Lay the watch face down on the cloth.
2. Slide the forked tip between the strap and the lug, keeping the tool angled towards the strap and away from the case.
3. Catch the shoulder of the spring bar with the fork and press gently towards the centre of the strap until the pin leaves the lug hole.
4. Lift that end out and pull the strap free.
5. To fit a strap with standard bars, seat one end of the bar in its lug hole, compress the other end with the fork, slide it into place and release. Test it with a tug.

Some watches have drilled lugs, with a small hole through the outside of each lug. On these you can push the pin inwards from outside with a fine tool, which keeps the tool out of the gap between strap and lugs; work carefully, as the tip is still close to the outside of the lug.

How to avoid scratching the case

A slipping tool is a common cause of marks during a strap change. A few habits make it less likely:

• If you like, cover the inner faces of the lugs with low-tack masking tape before using a spring bar tool. It is optional, but it gives the case some protection if the tool slips.
• Work slowly, with the watch resting on the table and your hands steady, rather than on your lap or in your hand.
• Keep the tool tip pointed at the strap, not at the case.
• Use quick-release spring bars where you can, since there is usually no tool near the case at all.
• If a spring bar is stuck, tight or bent, stop. Forcing it is how lugs get marked, and a watchmaker can remove it for you.

After fitting: a quick check

Buckle the strap on your wrist and look at where it meets the case. The leather should sit neatly between the lugs, without gaps at the sides and without bunching. Move your wrist around: the strap should hinge freely at the spring bar.

A new leather strap may feel firm at first, and many leathers shape to the wrist with wear. If the length is wrong rather than the feel, the sizing guide explains how lug-to-lug length and wrist size work together. For an unusual lug width, thickness or length, the custom strap builder lets you set each one. Once the new strap is on, our guide to caring for a leather watch strap covers cleaning, drying and storage.

Frequently asked questions

Do I need tools to change a Cernir strap?

Usually not. Each strap comes with two quick-release spring bars fitted, so in most cases you can swap it by hand. Some lug shapes leave little room for your fingernail, and you need a spring bar tool to remove an old strap that uses standard bars.

Can I reuse the spring bars from my old strap?

You can if they are the right length for your lug width and are straight and springy. Bent or weak bars should be replaced, since they are what holds the watch to the strap.

Will quick-release bars fit my watch?

They usually fit watches where the strap attaches with a spring bar between two lugs. Watches with integrated bracelets or brand-specific fittings may not take a standard strap at all. If you are moving a Rolex from its bracelet to leather, our guide to fitting a leather strap on a Rolex covers clearance at the lugs and spring bars.

How often can I change straps?

As often as you like. Quick-release bars are made for regular swapping, which makes it easy to try a different slim strap on the same watch. Rotating straps also gives each one time to dry out between wears.