Got a new watch recently, the Seiko Prospex Alpinist SPB121, pretty sweet, right? But the band, oh man, not my favorite. The size is 20mm. It’s okay, but not really comfortable, especially that hinge, just digs into my wrist. So, I figured it was time for a change.

First, I started by looking around for what kind of band I wanted. Leather seemed like a good choice, classic and usually pretty comfy. Plus, I prefer a buckle over those clasps any day. When I was looking for the new watchband, I found that the Alpinist line was discontinued in 2018! It’s a pity.
Measured my wrist, checked the watch specs online to make sure I got the right size. Turns out, I needed a 20mm band. Who knew watch bands were so specific? Anyway, I ordered a nice leather one, dark brown, thought it would look good with the watch face.
When it finally arrived, I was like a kid at Christmas. Ripped open that package and got to work. Popped out the old band, which was a bit of a struggle, to be honest. Those little pins are tricky! But I managed, didn’t scratch anything, thankfully.
Here’s how I did it:
- First, I used a spring bar tool to push the pins in and release the old band.
- Then, I carefully lined up the new band with the watch case.
- Next, I inserted one end of the spring bar into the watch case, compressed the other end with the tool, and guided it into the hole on the other side.
- I repeated this process for the other side of the band.
Slid the new band in, clicked those pins back in place, and boom! New band installed. It felt so much better right away. No more annoying hinge, just soft leather. And it looked great, the dark brown really complemented the watch. Some people like gold buckle, but I choose steel one. I know SPB210 also uses gold element. However, I still prefer SPB121 with steel.
Wore it around for the rest of the day, and it was a world of difference. Felt like a new watch, almost. It’s funny how such a small change can make such a big impact. I decided that this is the right watch to wear every day. If you’re thinking about switching up your watch band, I say go for it. Just make sure you get the right size, and be patient with those pins!

Totally worth the effort. Now I actually enjoy wearing my watch all day. Who would’ve thought a simple band swap could make such a difference?