Over the past 2 yes I've bought 3 F91W. The band keeps breaking. Does anyone have a suggestion on how to get a better band? I didn't seem like changing band is doable without appropriate tools, and furthermore I don't know how to ensure I know his to buy a band that is "compatible".
Same problem with F-105. Constant exposure to pool water seems to kill the wristband. I just got a black elastic band from a haberdashery store and experimented with it. My final solution is to cut a segment, seal both ends with superglue (to keep rubber strands fixed to the band structure) and fold over the pins and sew ends (used black dental floss since all I had at the time). Band is 20mm wide which is a tad too wide but works fine for me. It is very comfortable and I am never going back to a stock bands. They were selling the elastic band by the meter so I have enough for a decade or so.
https://www.reddit.com/r/F91Ws_on_NATOs/
It's a pretty common mod, the sidebar describes the process and mentions using 18mm nato straps, though apparently you might want to grind a little off the back of the lug to make it fit better. It also mentions using a paperclip or some other pin to get the spring bar out, so it doesn't seem like it requires much.
Thanks for the suggestion, but no. That seems really dangerous. If it gets stuck somewhere heavy or fast, that strap looks like it can take more than your body weight with it...
The F-91W has 18mm lugs, but it uses a friction-held (non-spring) bar, which limits your options. Further limiting it is that it doesn't quite look right without the flare out and taper. Some people don't mind this and swap it with a 18mm NATO strap and just wear it like that indefinitely.
I solved this problem by going on Aliexpress and ordering replacement metal band that fits the F-91w, A-158, and similar models. It costed $4.98. Been using it ever since and it works great. Being metal, now it's the least fragile part of the watch. You can also just upgrade to the ~$20 A-158, or one of the other metal band Casios, and get that out of the box. Timex also makes the T80 with a metal band as well.
I slightly prefer the light weight of the plastic band, but if you're okay with a metal band and your arm isn't too hairy (these low end metal bands like these can be painful if you are), then that's an option. The only tool you'll need to replace this is a spring bar tool that has the straight poker end or something similar.
It's a bit fiddly to change watch straps on a F91W. You want to put spring bars in there, which is what watch straps attach to, and you'll have to use a bit of force. A sharp knife helps.
There are plenty of almost-similar models, with the same low prices and some have standard lugs. The A158W is one of them. Then buy any strap you want, leather or textile are nice and cheap.
It’s super annoying because those bands cost pennies each to make yet by the time they are individually packaged, they are $10 ea. I wish I could buy a lifetime supply. Maybe 50 for $50.
The A1000 line has a metal case, while the A158 has a resin case that is chrome plated. They might be a different size, and they have different specs for weight and battery life. The A1000MA is kind of a buy-it-for-life-grade version of the A158 that recently came out.
