I have a lot of different Spyderco models and enjoy them all. I always have a hard time picking favorites but the Mantra is definitely one that I'd have a hard time letting go of should I ever need to liquidate my collection.
For me there's just so much to like about the Mantra. The Delica-like ergos, multiple opening methods, wire clip, blade shape, M4 steel, and a cutting edge that's longer than Manix 2 and PM2 but in a smaller package. The only thing that kind of bothered me about my Mantra was the weak detent. I could flip it ok. So the weak detent wasn't really a show stopper for me. Still I couldn't help but wonder how much better it would flip if the detent was a little stronger. So now that I know how to improve the detent, I figured after 2 1/2 years it was time to take the knife apart for a good cleaning and a little modification to the hole the detent ball rests in when the blade is closed.
When I took the knife apart I noticed an issue right away.
I have a couple other Spydies with a little flat spot on the detent ball but nothing that looks like this. I'm not even sure what to make of the big step in what's supposed to be a ball. All I can think of is the step was left from whatever tool the Taichung factory used to press the ball in. I can see how the flat spot could happen through use but I find it hard to believe that opening and closing the knife caused that step all the way around the ball. Although I've been wrong at least a few times in my life.
I decided it didn't make sense to mess with the detent ball hole with the ball in the condition it was in. I considered ordering some ceramic balls to replace the deformed steel one but decided to see what flipping the ball would do first. So I took the lock bar insert off. Before driving the ball out I measured the protrusion and it was .015". I used a small punch to push the ball out into a small hole I drilled into the wood block I was resting the lock bar insert on. Then I repositioned the ball back in the hole so the undamaged part was exposed and I tapped the ball back in with a little mallet I have. All looked fine but ball was protruding. 025" and it looked like too much was sticking out. I couldn't seem to drive it in any farther with that little mallet and I didn't want to risk ruining the good side by whacking it with something bigger. So I got my little arbor press out and pushed it in another .004".
I wish now I would've taken a pic of the ball at this point for comparison sake. I guess you"ll just have to take my word that it looks much better now (round). After reassembling the knife I was amazed by how much better it works too. The flipping action is much improved. So much so that I no longer feel the need to improve upon it further. The detent still isn't as strong as some of my other dedicated flippers but it's plenty snappy. I think it's just about right for using the opening hole or flipper tab to open the knife.
As I said, this Mantra is one of my favorite knives. Now that the detent is the way it should be it's more enjoyable than ever.