Detent - How weak is too weak?

[burley_c]

I recently picked up a Kapara. I like the knife a lot, but I've noticed that the detent is weak. You can notice the detent and a light bias toward closing, but unlike my other Spyderco compression lock knives, I can open it all the way to the locking position with a hard snap of the wrist. I definitely cannot do with this my PM2 or Sage 5.

It was a factory second and advertised as such, so I knew what I was getting into. What I'd like to know is, at what point is a weak detent on a compression lock a safety issue?

[Danke]

It's a problem if you can shake the knife open.

[burley_c]

Thanks, @Danke !

I knew a weak detent was a risk with a factory second. I'll start looking into how to fix this. If I can't, it may end up in a bag as a decided food prep knife for pool and beach days or camping trips.

[vivi]

Can I shake it open?

Can I open it by dropping it into a carpet floor from 3-5'?

Can it pop open if I'm carrying it clipped to the waistband of my shorts and I go for a short run?

Will it open if I put it in a backpack and the backpack gets tossed around a bit?

If the answer to any of those is yes, it's too weak for my tastes.

Most detent based locks fail #2 pretty consistently.

I'd like to see more locks like lockbacks and CBBL that have a strong closing bias.

Thanks, @Danke !

I knew a weak detent was a risk with a factory second. I'll start looking into how to fix this. If I can't, it may end up in a bag as a decided food prep knife for pool and beach days or camping trips.

Still be careful if you do. I've had knives with weak detents come open in my pack on day hikes before. Luckily I spotted it before reaching into the bag and hurting myself.

[burley_c]

Still be careful if you do. I've had knives with weak detents come open in my pack on day hikes before. Luckily I spotted it before reaching into the bag and hurting myself.

That's a good point. Hopefully it's something I can fix. It would be a shame to have to relegate such a nice knife to a drawer.

[silver & black]

Use a cone shaped grinding stone in a Dremel to deepen the hole that the detent ball sits in. Very small increments until you get what you want. Make sure the point of the grinding stone is hitting the bottom of the hole before starting. I've strengthened many detens like this. Narrower stone are best so as not to widen the dia. of the hole.

[burley_c]

Thanks @silver&black, I'll give this a shot tomorrow when I'm a little more rested.

[sal]

Hi Burley_c,

You might consider a very slight more bend in the lock bar that holds the ball bearing? A slight increase in pressure might solve your issue? Might be a little harder to unlock?

sal

[zhyla]

Can I shake it open?

Is there really a liner lock / compression lock that can’t be shaken past its detente?

[Flash]

It’s too weak if the blade of your compression lock Lil Native comes open in your cargo pant pocket and the tip stabs into the side of your leg whilst you climb a fence.
Fortunately this has never happened with my other regular carries; UKPK, Chaparral or Native 5 but the Lil Native has been relegated to non-carry use only.

[horzuff]

Can I shake it open?

Is there really a liner lock / compression lock that can’t be shaken past its detente?

I don't think there's any lock that has some kind of detent mechanism that can't be shaken out with enough effort :D. But I guess he meant a reasonable shake and most of my liner/frame/compression locks can do that.

[silver & black]

Can I shake it open?

Is there really a liner lock / compression lock that can’t be shaken past its detente?

I haven't found one that can't be shaken open.

[burley_c]

Can I shake it open?

Is there really a liner lock / compression lock that can’t be shaken past its detente?

Edit: I spent some time comparing my compression lock knives to my backlock knives, and it does seem like the compression lock knives *could* pop open in ways that backlock knives won't. Probably not a huge deal, but side by side the difference was much more pronounced than I would have expected.

[Actinolite]

I have a Sage 1 that is not a factory second. I didn’t notice a weaker detent until one day I found it open in my pocket. I compared it to other knives kept closed with a detent ball. It was weaker than others, but not by much.

After this, I decided to predominantly pocket carry only knives that have a strong closing bias. If I carry a liner lock or compression lock, I carry it with the blade wedged closed against the pocket edge.

[horzuff]

Can I shake it open?

Is there really a liner lock / compression lock that can’t be shaken past its detente?

Sure is. I have a Sage 5 along with one of the new PM2 LW's in SE, both of which have a rock solid detent. I'm a large guy and trying my darndest, there's no way I can shake past the detent on either of those knives. That's what led me to ask the question here about the kapara.

Grab it upside down, by the clip, blade spine forward and try a whip like move. With enough gusto You can open absolutely any knife that doesn't need to be released with a button or something

[Evil D]

I'd rather not be able to inertia open my knives. It's not something I do on purpose and I think if it's strong enough to prevent that then it's probably strong enough to keep me happy.

[M_J87]

Can I open it by dropping it into a carpet floor from 3-5'?

This is ultimately what made me sell my one and only PM2. I've been lock back since.

[kobold]

it opens in my pocket

[Danke]

Grab it upside down, by the clip, blade spine forward and try a whip like move. With enough gusto You can open absolutely any knife that doesn't need to be released with a button or something

New York Flick

[Coastal]

I'd rather not be able to inertia open my knives. It's not something I do on purpose and I think if it's strong enough to prevent that then it's probably strong enough to keep me happy.

This is how I feel, too.

In my mall ninja days, I almost wouldn't buy a folder that I couldn't flick open. Then one of them opened in my pocket, got wedged in, and sliced my finger as I wrestled it out. Since then I've been a strong detent guy, and if the knife allows it, tip down. As I've gotten older I can't whip many of them open anymore, and that's fine with me.