I acquired 2 different deployment clasps and had the opportunity to use them as daily wear for some time. Thought I'd chime in and share some input on my observations.
Hirsch Sport
I acquired the 18mm Hirsch Sport, a single-fold deployment clasp, through WatchObsession to pair with the Hirsch Liberty straps I picked up. Build quality is excellent, really solid. Initially ordered a regular sized one, which couldn't be used because it can only take straps of up to 3.7mm thickness of straps. Had to get the plus-sized variant to accomodate the Liberty strap (4.0mm). Fitting a thick strap onto a clasp does take some effort, but otherwise it works as advertised. I must admit, it doesn't fit my 7in wrist quite as comfy as I would like. The metal fold does press a bit against the skin over my radial bone if strap adjustment is fit snug, either due to size or shape of my wrist. I'm often consciously aware of the strap being there (typically for straps with a buckle, u won't really "rasa" the watch, its just there firm and comfy against the skin of the wrist). Set the strap too loose and the watch becomes like a bangle. Over time I have gotten used to the sensation of the clasp against my skin and its fine, its not a deal breaker by any means. I just feel that it could be better. Which brings us nicely to the next clasp;
Omega-style
I picked up a 16mm China-made clone of the Omega AT single-fold clasp. I decided on this after having tried out an AT with a rubber strap one fine day and realizing that this was THE most comfy single-fold I have ever used, period. I believe this is mainly due to the way the clasp itself folds - it tucks the strap inwards rather than outwards. This means that its the strap material that presses against our skin, not the metal of the folding clasp. Since the Omega clasp costs in excess of RM1k and the cloned variant is barely RM50, the choice was a no brainer lah. The build quality is good, but the release mechanism can be finicky a bit - once in a while I have to fiddle with it slightly to loosen it. Considering the comfort it presents, to me, its really a non-issue. One important thing to bear in mind, these style clasps have really thin strap clearance la, like seriously nipis (buckle end thickness 2mm, maybe 2.5mm max for a really snug fit). Other than that they work really nicely. Since they fold inwards, your strap retainers won't be seeing much use. Also, you will need to mind the overall dimensions of the strap - if its not designed as an Omega strap, u need to make sure the thickness is within 2.0mm and the strap length is actually long enough to accomodate wearing it on your wrist. Using it on my existing strap (2.5mm thickness, 120/80mm length), I can just about fit it onto the clasp and just long enough to fit my wrist (using the very first pin buckle hole). All in all, I highly recommend this clasp format.
End note: when purchasing after market clasps, I now take note of the following:
- Try them on if u can (best case scenario)
- Read reviews and learn about its width and thickness clearances.
- Check this against the buckle-end dimensions of the strap u intend to Macguyver, make sure they fit
- Find out fitment on small, medium or large wrists. Also consider shape of wrists.
- How the single clasp actually folds - does it fold the strap outwards (meaning clasp fold is inner-most and against the skin) or inwards (meaning strap material is inner-most and against the skin).
*Note these observations I made are specifically for single fold clasps only. YMMV.