Sebenza 31 Lock Rock?!

Status
Not open for further replies.
bmilleker said:
Shouldn't the pivot bushing be smaller? I always thought it was the pivot bushing + washers that should equal the width of the stop pin and standoff?
Click to expand...
Sharp & Fiery said:
The pivot bushing being slightly taller than the washers is why you can tighten the pivot screw to max tightness. Then the blade actually rotates around the bushing.
Click to expand...
Sharp is correct.

Washer/Grease
BLADE
Washer/Grease

The thickness of the sandwich above should perfectly match the thickness of the pivot bushing, stop pin (collar on the 21, shoulder to shoulder on the 31 unless there is shoulder nesting?), backspacer heights.
 
hoimin said:
Yes, the female ends nest in for sure. Does any of the stop pin shoulder sink into the scale, i.e. is the stop pin hole countersunk both on the outside (for the screw head) and on the inside (for the shoulder)? Or does the stop pin shoulder sit right against the scale while the female ends go through?
Click to expand...

Sorry, I misunderstood your question. The shoulder of the pin sits on the scale and its not recessed. This applies for both scales.
 
Thanks to those who have taken the time to post their findings. I hope CRK does properly address this. I really love their "nothing but the best" attitude and I understand their pricing. I think the price is fair and justified provided they deliver on the quality. In my opinion a large part what you are paying for is said quality. I am sure the side to side play and pivot bushing issues can be corrected by replacing components and tuning things at the factory. I don't think the up/down play can be easily addresses. I think that the issue is partially magnified by the ball bearing interface but it is likely the triangle created by the stop pin, pivot and lock interface.

Before I get into this I want to clarify I am no expert and this is just my theory. On the 21 the triangle is different because the blade locks up at the outer most edge of the lock face. The surface area of engagement is also larger than the single point of the ceramic ball. From the pictures it looks like the ceramic ball is located near the center of the lock bar. this allows for the blade to gain more leverage over the lock bar when negative pressure is applied. It also means that the same amount of movement at the tip will result in more inward flex of the lockbar.

It sounds like the Inkosi doesn't seem to have the same issue. I understand that it can flex (they all can flex), but no one seems to be complaining that you can grab the blade with two fingers and move it around with minimal effort. I don't own one so I cant say for sure. I would love to see some pics comparing the two disassembled to show the lockup triangles compared.

I have read the posts showing the flex when the knife is laid on a table and pressure applied to the spine. I don't think this is an issue at all and is inherent to framelocks in general. I do think its an issue if it flexes when checking for blade play normally in your hands. I really hope CRK comes up with something to fix this. I don't think the responses I have seen so far are sufficient. More importantly I hope they properly take care of people who are having this issue right now.

It seems not everyone agrees the price is justified but prior to this thread I thought it was basically universally accepted that their quality is top notch. It would be a shame to see the reputation of such a great company tarnished. In this market segment reputation is very important. If you get the odd bad Kershaw I don't think anyone would drastically change their view of the brand but when you are at the high end of pricing for a given segment of the market (production knives) people have different expectations.

I do like the design and if they address these issues I will pick up a 31. I understand that the current situation limits their capability to address the issue.
 
Stang Bladeworks said:
Thanks to those who have taken the time to post their findings. I hope CRK does properly address this. I really love their "nothing but the best" attitude and I understand their pricing. I think the price is fair and justified provided they deliver on the quality. In my opinion a large part what you are paying for is said quality. I am sure the side to side play and pivot bushing issues can be corrected by replacing components and tuning things at the factory. I don't think the up/down play can be easily addresses. I think that the issue is partially magnified by the ball bearing interface but it is likely the triangle created by the stop pin, pivot and lock interface.

Before I get into this I want to clarify I am no expert and this is just my theory. On the 21 the triangle is different because the blade locks up at the outer most edge of the lock face. The surface area of engagement is also larger than the single point of the ceramic ball. From the pictures it looks like the ceramic ball is located near the center of the lock bar. this allows for the blade to gain more leverage over the lock bar when negative pressure is applied. It also means that the same amount of movement at the tip will result in more inward flex of the lockbar.

It sounds like the Inkosi doesn't seem to have the same issue. I understand that it can flex (they all can flex), but no one seems to be complaining that you can grab the blade with two fingers and move it around with minimal effort. I don't own one so I cant say for sure. I would love to see some pics comparing the two disassembled to show the lockup triangles compared.

I have read the posts showing the flex when the knife is laid on a table and pressure applied to the spine. I don't think this is an issue at all and is inherent to framelocks in general. I do think its an issue if it flexes when checking for blade play normally in your hands. I really hope CRK comes up with something to fix this. I don't think the responses I have seen so far are sufficient. More importantly I hope they properly take care of people who are having this issue right now.

It seems not everyone agrees the price is justified but prior to this thread I thought it was basically universally accepted that their quality is top notch. It would be a shame to see the reputation of such a great company tarnished. In this market segment reputation is very important. If you get the odd bad Kershaw I don't think anyone would drastically change their view of the brand but when you are at the high end of pricing for a given segment of the market (production knives) people have different expectations.

I do like the design and if they address these issues I will pick up a 31. I understand that the current situation limits their capability to address the issue.
Click to expand...

Good to see you here Derek. I agree with the “triangle” being off as stated earlier. Also keep in mind that the Inkosi scales are slightly thicker and therefore would aid in being less prone to flex.

The table flex thing, in my opinion as well, is overkill. But when I can create this flex with just pinching the end of the blade with one hand and holding the handle with my other hand...this is an issue to me.

Also, my 31, in my opinion, will not go to full lockup position.
 
Sharp & Fiery said:
Good to see you here Derek. I agree with the “triangle” being off as stated earlier. Also keep in mind that the Inkosi scales are slightly thicker and therefore would aid in being less prone to flex.

The table flex thing, in my opinion as well, is overkill. But when I can create this flex with just pinching the end of the blade with one hand and holding the handle with my other hand...this is an issue to me.

Also, my 31, in my opinion, will not go to full lockup position.
Click to expand...
Thanks,

My thinking is that the thickness of the titanium doesn't matter here because the flex is occurring in the lockbar relief. I don't know if that is thicker as well on the Inkosi, but if my memory is correct the Sebenza 21 is about .060" which is pretty thick. That is why the lockbar tension is so high. It has a thicker relief than any other framelock I own. I would be curious if the 31 has a different spec. That could be one explanation as to the cause of this.

I have seen framelocks with a .040" relief that do not exhibit this flex. If you open the knife partially and press the lockbar in towards the back of the frame you can get a feel for how difficult it is to flex. It would be a good comparison to see how this feels from the 21 to the 31. I would use a micrometer if possible to measure the relief to get the best number possible.

In my opinion not providing a legitimate response is hurting them. It allows dummies like me to speculate instead of just addressing the issue head on. I understand its more complicated than that but in general owning a situation is the best approach. I am sure not every 31 has this issue but every youtube video has comments about lock rock. Instagram is the same. It seems to be widespread enough that people are talking about it.

The worst part is that when you first look deeper the most readily available info is the response that its normal. I know Tim has later said that they are looking into it after this is all over but it would go a long way to provide the community a thorough response and a potential plan of action or at least detail how existing customers will be taken care of.

I really like CRK and I do have confidence they will make this right. They seem like a great company founded on principals that us knife enthusiast value highly.
 
I’ve got a L 21, L Inkosi, and an Umnumzaan, so I’ve got a pretty good sample of lock-up. My 31 is no different than the other two with ceramic ball interface. Here is a quick video showing mine. Scales date 4th quarter 2019. Birthdate is March 2020. Pretty good action already.

https://imgur.com/gallery/vTJI2wY
 
jfowler1 said:
I’ve got a L 21, L Inkosi, and an Umnumzaan, so I’ve got a pretty good sample of lock-up. My 31 is no different than the other two with ceramic ball interface. Here is a quick video showing mine. Scales date 4th quarter 2019. Birthdate is March 2020. Pretty good action already.

https://imgur.com/gallery/vTJI2wY
Click to expand...
Thanks for deets. I wish I could say the same. Thumb flick (cries inside). Congrat's. Looks like a gem.
 
So, out of curiosity...if you have a 31 with issues or not...state model and ok/issues?

Mine is an inlay - issues.
 
Ptman2000 said:
I received a reply today about my 31.

CRK said that they had a meeting about these issues just before they had to close but weren’t able to come up with anything.
Click to expand...

Sorry, they weren’t able to come up with a solution? Or the issues they couldnt replicate?
 
Ptman2000 said:
didn’t come up with a solution before they had to close the office.
Click to expand...

Thank you. :) Im personally giving CRK slack right now especially with the current situation.
It is somewhat fun trying to come up with a solution with the gang here on BF.
 
Status
Not open for further replies.
Back
Top