- Joined
- Jan 12, 2013
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- 3,155
Ok fellas and gals,
I have been carrying a CRK in my pocket, (mainly Sebenzas) on most days of my life, for just over three years. Give or take a few weeks with other things taking their place, that's about 1000 days of carry. In that time I have learned a few things about smoothness:
1 - 95% of the time the issue with your CRK feeling "gritty" will be contamination of the detent track (the tiny groove worn on the edge of the side of the blade heal by the detent ball), not the pivot. The reason why overhauling the pivot and re-greasing, or polishing the washers, etc, seems to fix the problem is that you likely end up cleaning the detent track without necessarily making that your primary intention.
2 - The biggest culprit for "grittyness" is not actually grit, but usually residue of some kind, especially dried fruit juice, but also other stuff contaminating the detent track. This causes the small ceramic detent ball in the 21, and the larger ceramic detent/lock ball on the Sebenza 25, to grab and skip it's way along the track rather than sliding along, causing the gritty feeling.
3 - The reason Chris Reeve knives can be so very smooth, is that CRK uses Ceramic detent balls, and if the groove is free of residue, the co-efficient of friction is very low between the ceramic and the steel of the blade. The typical steel-on-steel of more generic type knives is more likely to have stiction as steel grips steel under pressure (think railway locomotive wheels). In another famously smooth knife, the Spyderco PM2, the knife can be very smooth even with a steel detent ball. This is because when you unlock the PM2, you are holding the detent ball right off of the blade via the workings of the Spyderco compression lock system. With a CRK framelock, once you release the lock, the ball drags along the blade all the way to the lock divot. With this being the case, CRK went for a ceramic ball on their framelocks, and the rest is history as they say. A very smooth solution, but it is not without it's problems.
So......of course "your mileage may vary", but in my opinion these points hold true in most cases. To prove this, and as a very handy troubleshooting tool, I developed the "CHOPSTICK METHOD".
It is simple. If you want to determine if a "gritty" Sebenza pivot is due to lack of grease or issues with the pivot, or if it's contamination of the detent track, you need to lift the lockbar slightly clear of the blade, so the detent ball is just above the blade. At this point the blade will be free to rotate. I use a thin tapered Choptsick. I lift the lockbar slightly by hand, and then wedge the chopsitck in place to hold the detent ball just above the track. In most cases, you will find the blade is now swinging completely smooth and free, and the issue with the gritty pivot has something to do with gunk on the detent. To resolve this you can either wash the knife assembled (this is what I do) or take it apart, if you must, while paying specific attention to cleaning the detent track. For me, washing under the sink with mild pump handsoap seems to work fine. Others have had problems with this, so your gotta do what works for you. Some soaps may also leave a reside....who knows. Also you may be able to clean the detent track my another means, say with WD40 and a Q-Tip or something. The main point of the CHOPSTICK METHOD is to alert you to where the problem is. Not solve it.
After learning this technique, I found almost all of my issues were from letting fruit juice dry on the detent. When I use my knife to cut up fruit (most days), I try to give it a quick rinse in plain water before any juice dries on the track. This has kept my knives smooth at almost all times.
You can use a cheap wood chopstick, or an expensive Ming Dynasty jade chopstick, or a purple plastic one as shown here. Just make sure it is one of the thin tapered type of chopsticks, or whittle it down a bit if it is too thick to easily go between the slabs. Remember: you do not want to force anything in there, and bend the lockbar, or change it's tension. You just want to lift the lockbar ever so slightly off the blade. Once that detent ball is lifted up, you will be absolutely amazed how free swinging the average sebenza is.
If nothing else, you now have decent reason to order Chinese take out!
I have been carrying a CRK in my pocket, (mainly Sebenzas) on most days of my life, for just over three years. Give or take a few weeks with other things taking their place, that's about 1000 days of carry. In that time I have learned a few things about smoothness:
1 - 95% of the time the issue with your CRK feeling "gritty" will be contamination of the detent track (the tiny groove worn on the edge of the side of the blade heal by the detent ball), not the pivot. The reason why overhauling the pivot and re-greasing, or polishing the washers, etc, seems to fix the problem is that you likely end up cleaning the detent track without necessarily making that your primary intention.
2 - The biggest culprit for "grittyness" is not actually grit, but usually residue of some kind, especially dried fruit juice, but also other stuff contaminating the detent track. This causes the small ceramic detent ball in the 21, and the larger ceramic detent/lock ball on the Sebenza 25, to grab and skip it's way along the track rather than sliding along, causing the gritty feeling.
3 - The reason Chris Reeve knives can be so very smooth, is that CRK uses Ceramic detent balls, and if the groove is free of residue, the co-efficient of friction is very low between the ceramic and the steel of the blade. The typical steel-on-steel of more generic type knives is more likely to have stiction as steel grips steel under pressure (think railway locomotive wheels). In another famously smooth knife, the Spyderco PM2, the knife can be very smooth even with a steel detent ball. This is because when you unlock the PM2, you are holding the detent ball right off of the blade via the workings of the Spyderco compression lock system. With a CRK framelock, once you release the lock, the ball drags along the blade all the way to the lock divot. With this being the case, CRK went for a ceramic ball on their framelocks, and the rest is history as they say. A very smooth solution, but it is not without it's problems.
So......of course "your mileage may vary", but in my opinion these points hold true in most cases. To prove this, and as a very handy troubleshooting tool, I developed the "CHOPSTICK METHOD".
It is simple. If you want to determine if a "gritty" Sebenza pivot is due to lack of grease or issues with the pivot, or if it's contamination of the detent track, you need to lift the lockbar slightly clear of the blade, so the detent ball is just above the blade. At this point the blade will be free to rotate. I use a thin tapered Choptsick. I lift the lockbar slightly by hand, and then wedge the chopsitck in place to hold the detent ball just above the track. In most cases, you will find the blade is now swinging completely smooth and free, and the issue with the gritty pivot has something to do with gunk on the detent. To resolve this you can either wash the knife assembled (this is what I do) or take it apart, if you must, while paying specific attention to cleaning the detent track. For me, washing under the sink with mild pump handsoap seems to work fine. Others have had problems with this, so your gotta do what works for you. Some soaps may also leave a reside....who knows. Also you may be able to clean the detent track my another means, say with WD40 and a Q-Tip or something. The main point of the CHOPSTICK METHOD is to alert you to where the problem is. Not solve it.
After learning this technique, I found almost all of my issues were from letting fruit juice dry on the detent. When I use my knife to cut up fruit (most days), I try to give it a quick rinse in plain water before any juice dries on the track. This has kept my knives smooth at almost all times.
You can use a cheap wood chopstick, or an expensive Ming Dynasty jade chopstick, or a purple plastic one as shown here. Just make sure it is one of the thin tapered type of chopsticks, or whittle it down a bit if it is too thick to easily go between the slabs. Remember: you do not want to force anything in there, and bend the lockbar, or change it's tension. You just want to lift the lockbar ever so slightly off the blade. Once that detent ball is lifted up, you will be absolutely amazed how free swinging the average sebenza is.
If nothing else, you now have decent reason to order Chinese take out!
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