Sebenza 31 Lock Rock?!

[kidcongo]

The TI slabs are the same but thickness between all large models. The lockbar on both the Umnumzaan and the inkosi is cut closer to the edge of the slab at the start, but angles inwards into the slab when you look at it.

 

[nyefmaker]

I stated in an early post this exact question. I also believe the lockbar is too thin, and the blade thickness is too thin for the size of the ceramic ball they are using.

These are my thoughts as well. The slabs and blade thickness is the same as a 21, but the blade stock is thinner than the zaan, 25, inkosi. With the blade being thinner, lot less real-estate for the ceramic ball to lockup. The Sebenza 21 wasn’t broke, there was no need to fix it.

 

[jonnieb27]

It would be fascinating to know just how much input Chris Reeve had into the changes to the Sebenza 31, if any.

It strikes me that the changes are largely an attempt to streamline production and create renewed interest in an already optimized product.

I don't think many people would understand just how single-minded Chris Reeve was in his drive to provide a superior product, and to set himself apart from other knife builders when he moved to the US. (While I admire that drive, I don't, unfortunately, share it) That kind of commitment is not easily transferred, even between family members. Once the driving force behind the idea of the "Sebenza", Reeve integral lock, etc left the building, it is not difficult to imagine that (his) 24/7 dedication to putting out the best possible product might wane in subsequent generations, or iterations of the product.

Mr. Reeve was a machinist and a craftsman of the highest order. "Do the **** job right, or don't do it at all" sums up his philosophy nicely.

Does the 31 live up to that standard? Only time will tell.

 

[warmartyr]

I just checked my Umnumzaan against my two sebenza 31's and both have this flex. Does it matter? If so, why wasn't it discussed when the Umnumzaan came out and the many years afterwards?

 

[MreeceC]

It would be fascinating to know just how much input Chris Reeve had into the changes to the Sebenza 31, if any.

It strikes me that the changes are largely an attempt to streamline production and create renewed interest in an already optimized product.

I don't think many people would understand just how single-minded Chris Reeve was in his drive to provide a superior product, and to set himself apart from other knife builders when he moved to the US. (While I admire that drive, I don't, unfortunately, share it) That kind of commitment is not easily transferred, even between family members. Once the driving force behind the idea of the "Sebenza", Reeve integral lock, etc left the building, it is not difficult to imagine that (his) 24/7 dedication to putting out the best possible product might wane in subsequent generations, or iterations of the product.

Mr. Reeve was a machinist and a craftsman of the highest order. "Do the **** job right, or don't do it at all" sums up his philosophy nicely.



Does the 31 live up to that standard? Only time will tell.

These are my thoughts as well. The slabs and blade thickness is the same as a 21, but the blade stock is thinner than the zaan, 25, inkosi. With the blade being thinner, lot less real-estate for the ceramic ball to lockup. The Sebenza 21 wasn’t broke, there was no need to fix it.

Could not agree more! Again I will ask.... What was "wrong" with the 21? And I could care less about how stream line your production is. Not that the 31 has no place at CRK. I just really hard for me to see the 21 go. Maybe the slip joint before the 21....? I am sure I will get over it and CRK will perfect 31. Just hard in that transition time between the two to see how this thing will end if the 31 really will end up being as good as the 21. Also some good news is, we still have the Inkosi.

 

[BeaverTail_Hunter]

These are my thoughts as well. The slabs and blade thickness is the same as a 21, but the blade stock is thinner than the zaan, 25, inkosi. With the blade being thinner, lot less real-estate for the ceramic ball to lockup. The Sebenza 21 wasn’t broke, there was no need to fix it.

Technically, the didn't fix the Sebenza 21. The Sebenza 21 is still the 21. The created a new model of the Sebenza. The 31.

 

[BeaverTail_Hunter]

Could not agree more! Again I will ask.... What was "wrong" with the 21? And I could care less about how stream line your production is. Not that the 31 has no place at CRK. I just really hard for me to see the 21 go. Maybe the slip joint before the 21....? I am sure I will get over it and CRK will perfect 31. Just hard in that transition time between the two to see how this thing will end if the 31 really will end up being as good as the 21. Also some good news is, we still have the Inkosi.

It's not like the 21 has disappeared. It's still relatively easy to own most of the Sebenza models, even the out of production variations.

 

[loon#r]

There are a ton of 21s out there. Almost too many IMO. Perhaps that was planned.

 

[nyefmaker]

Technically, the didn't fix the Sebenza 21. The Sebenza 21 is still the 21. The created a new model of the Sebenza. The 31.

Technically I realize that . Just like Hinderer did not screw up the xm18 with the lockbar insert. You will always have two sides at min. Those for and those against. I have my reasons
To distrust a ceramic ball lockup as stated previously...... It however is a shame because of new options like one piece inserts and boomerang Damascus. Good thing there are plenty of Chris Reeve Designed knives still to be had.

 

[Sharp & Fiery]

Ok, so regarding my large micarta 31 with side/side play and easy up down “flex”/clicking.
One more time taking it down, cleaning, measuring with calipers, finding that the bushing was a lot (in machinists standards) taller than the washers, I decided to strop the P bushing. Took away the side/side play. Blade is still centered, and the action is how a sebenza should be. The smaller lockside washer is slightly cupped, which bugs me. The lockbar flex bugs me. But...
Im just gonna beat on this one...see how it holds up. Im more willing to do this now that the side/side play is gone.

*I had mentioned earlier that it was going back to CRK. This was true, but I forgot to bring it on my travels to my buddies shop. Was supposed to drop it off to go back to CRK this monday.*

 

[BeaverTail_Hunter]

Technically I realize that . Just like Hinderer did not screw up the xm18 with the lockbar insert. You will always have two sides at min. Those for and those against. I have my reasons
To distrust a ceramic ball lockup as stated previously...... It however is a shame because of new options like one piece inserts and boomerang Damascus. Good thing there are plenty of Chris Reeve Designed knives still to be had.

Imagine a world where you could place an order for any Sebanza model (reg, classic, 21, 25, 31), any dammy blade, and all of the inlay styles. That would be a nice! Costly but nice!

 

[diracismyhero]

So I ponder these questions:

Is this whole aside the reason the lock bar is angled (not parallel to the centerline) on the umnumzaan and 25/Inkosi?

Is this issue the result of trying to implement the ball bearing lock with a thinner blade stock of the 31, compared to the Umnum and Inkosi?

I don’t know he answers, but I’m mulling it over in my mind.

For what it's worth, I put a large 21 blade into the handle of my 25 and there is exactly the same amount of movement as on my 25, which is very minimal. Nothing close to what I have seen on videos of the 31. I had to double up washers on the opposite side of the lockbar to account for the blade thickness difference. I am very sensitive to bladeplay/lockrock/lockflex, I can feel it on all my CRKs. However, as the blade is opened, the ceramic ball rides on the very edge of the blade. The "base?" of the blade is substantually wider on the 25 than the 21. From the edge of the pivot hole to the edge of the blade is 0.296in on the 25 and 0.259in on the 21.

I could be totally wrong in all of this, but my theory is that the 21 was designed from the ground up to work with a Ti/steel interface. The 25, Umnumzaan and Inkosi were all designed from the beginning to work with a ceramic ball. The 31 on the other hand, is a 21 with a ceramic ball, the geometry is wrong. However, Tim was put in a tough decision because he didn't want to change his father's famous design, but also wanted to streamline production with the other models and use a better locking system.

 

[kidcongo]

I think the only solution is to redesign the 31 to use a licensed version of Cold Steel’s Tri-ad lock. That would stop this thread, and be a “spine whackers delight”!

cheers all. I hope you all have a great weekend.

 

[nyefmaker]

Imagine a world where you could place an order for any Sebanza model (reg, classic, 21, 25, 31), any dammy blade, and all of the inlay styles. That would be a nice! Costly but nice!

For us old school CRK fans, that would be a dream come true and worth the cost...!

 

[Peter Hartwig]

It would be fascinating to know just how much input Chris Reeve had into the changes to the Sebenza 31, if any.

It strikes me that the changes are largely an attempt to streamline production and create renewed interest in an already optimized product.

I don't think many people would understand just how single-minded Chris Reeve was in his drive to provide a superior product, and to set himself apart from other knife builders when he moved to the US. (While I admire that drive, I don't, unfortunately, share it) That kind of commitment is not easily transferred, even between family members. Once the driving force behind the idea of the "Sebenza", Reeve integral lock, etc left the building, it is not difficult to imagine that (his) 24/7 dedication to putting out the best possible product might wane in subsequent generations, or iterations of the product.

Mr. Reeve was a machinist and a craftsman of the highest order. "Do the **** job right, or don't do it at all" sums up his philosophy nicely.

Does the 31 live up to that standard? Only time will tell.

It is never easy following a legend.
Personally I would have kept the 21 line alive. At least until something else proved it deserved replacing it.

 

[Anarchy84]

I may be 35 pages late to the party, but for what it’s worth neither of my 31’s have any play whatsoever. I can manhandle the blade in every direction and feel no flex at all. This leads me to believe this is an issue and not a feature.

While on the subject, I find it difficult to believe that a company who built its reputation on “bank vault” lockup would introduce blade play as a feature. That would be mind blowing.

 

[dano]

I just checked my Umnumzaan against my two sebenza 31's and both have this flex. Does it matter? If so, why wasn't it discussed when the Umnumzaan came out and the many years afterwards?

Becuase it didn't turn into a viral thread about an issue that is, essentially, a non-issue?

 

[hoimin]

The TI slabs are the same but thickness between all large models. The lockbar on both the Umnumzaan and the inkosi is cut closer to the edge of the slab at the start, but angles inwards into the slab when you look at it.

It took some google imaging to figure out what this meant; it’s quite clever!

The optimal contact point of the lock bar to blade tang lock face is as far from the pivot as possible. The optimal location for the ceramic detent ball to sit in the lock bar is the middle of the bar (most bread on either side of the ceramic sandwich meat).

So CRK cut the Umnumzaan and Inkosi lockbars as wedge shapes instead of parallel to the handle: normal width at the flex point and tapering towards the lock face. The result is the ceramic ball detent is shifted a bit lower and farther from the pivot by a few mm, yielding a stronger lock up.

 

[kidcongo]

It took some google imaging to figure out what this meant; it’s quite clever!

The optimal contact point of the lock bar to blade tang lock face is as far from the pivot as possible. The optimal location for the ceramic detent ball to sit in the lock bar is the middle of the bar (most bread on either side of the ceramic sandwich meat).

So CRK cut the Umnumzaan and Inkosi lockbars as wedge shapes instead of parallel to the handle: normal width at the flex point and tapering towards the lock face. The result is the ceramic ball detent is shifted a bit lower and farther from the pivot by a few mm, yielding a stronger lock up.

If you actually think about that slight angle on the Umnumzaan and Inkosi, the force coming off the blade tang is more perpendicular to the direction the lockbar might flex. Essentially, the ceramic ball is pushing the lockbar towards the back of the knife, rather than trying to flex it inwards. That slight angle of the lockbar cut on those two knives is not accidental, I would argue.

 

[353]

There are a ton of 21s out there. Almost too many IMO. Perhaps that was planned.

Off course there are a lot of 21's out there.

But try getting a pj small 21 at blade hq, knives ship free or knife art. They are GONE.

They are starting to dry up. And most of the guys owning one is likely to hold on to them, I know I am.