How I Made My Whoop 4.0 Band Work with the New Whoop 5.0

When I upgraded to the Whoop 5.0, I was excited for the new features — but disappointed to find that my old Whoop 4.0 bands no longer fit. The clip system had changed, and the new device uses slightly narrower bands and a redesigned clasp. Instead of throwing away my perfectly good 4.0 bands, I decided to fix the problem myself.

Here’s how I made my Whoop 4.0 bands fully compatible with the Whoop 5.0 — using a little sanding and a custom 3D-printed clip.

🆚 Step 1: Comparing the Bands

• Whoop 4.0 band width: 25 mm
• Whoop 5.0 band width: 24 mm

At first glance, the bands and clips look similar, but the new 5.0 system won’t accept the 4.0 band without modification. The clasp on the old band is just a bit too wide to fit.

🪚 Step 2: Modifying the Band

To make it work, I sanded down each side of the 4.0 clasp by 0.5 mm — for a total reduction of 1 mm. This made the end of the strap fit snugly into the new clip system.

I used a belt sander, but if you don’t have one, a file or even sandpaper will do the trick. It just takes a bit more time and patience.

🧱 Step 3: Designing a Custom Clip

To hold the modified band in place, I designed a custom 3D-printed clip:

• Based on the shape of the Whoop 5.0 clip
• Strap holes sized to fit the original 4.0 band width
• Created the side profile using polymer clay and transferred the shape into my 3D modeling software

This gave me a reliable, secure clip that works with the 4.0 strap — without forcing or bunching the material.

🖨️ Step 4: 3D Printing the Clip

I printed the clip using PLA filament. Each print took about 15 minutes, and I made a few test versions before getting the fit just right. The final clip locks into the 5.0 device firmly and lets the 4.0 band slide through naturally.

✅ Step 5: Final Fitment

With the strap trimmed and the custom clip in place, the result is perfect:
My old Whoop 4.0 bands are now fully compatible with the Whoop 5.0 device.

🛒 Want One?

If you'd like to order the custom 3D-printed clip, I’ve made it available:
👉 [https://shop.mrstukov.com/products/whoop-4-0-to-5-0-replacement-clip]

You’ll still need to sand your strap’s clasp by about 0.5 mm on each side, but everything else is ready to go.

💬 Questions?

Check out my full YouTube video showing every step.
Feel free to comment if you need tips, or message me if you'd like the STL file to print your own!

🛠 Recommended Tools

If you're interested in trying this project yourself, here are the tools I used or recommend:

🖨 3D Printer

I used a reliable desktop 3D printer for this project. Great for beginners and advanced users alike.
👉 Buy on Amazon

🎞 PLA Filament

I printed the clip using PLA filament. Choose a strong, high-quality brand for the best results.
👉 Buy PLA Filament on Amazon

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