In May of this year, I picked up my first Zero Tolerance knife – the 0550.  As I indicated in my review of the knife, I had some problems with the excessively strong detent (a not uncommon issue with the 0550/0551) but have grown to really like the knife.  So I ended up purchasing a 2nd ZT 0550 so I could have a little variety in their appearance thanks to the accessory scales which are available for these knives:

In the late August of 2012, Zero Tolerance started shipping a slightly updated version of the ZT 0550 – what many are referring to as the ZT 0550 Generation 2, or Gen 2.  The purpose of the updates to the 0550 seem to be to address some of the common complaints/concerns expressed with the ZT 0550 – issues which I discussed in my ZT 0550 Review back in may.  Nearly all the changes made can be seen from the titanium backside of the knife, as illustrated by this photograph of my ZT 0550 Gen 2 model:

The two most significant changes made which can be seen above are the addition of the “deep carry” pocket clip (the same one used on the ZT 0560/61) and the lockbar cut out (the square recessed area that can be seen located below the ZT logo on the pocket clip in the above photo) has been moved from beneath the lock bar to the outside of the lockbar.

To better illustrate the differences between the first generation ZT 0550, and the Gen 2 model, here’s a photograph which shows one of each side by side (Gen 2 on top):

The lockbar cut out change was made with the intention to reduce lockbar tension and make the knife easier/faster to open.  In my Gen 2 example however I found absolutely no improvement in the ease of opening knife as compared to my first generation model.  In my experience, the problem is more related to the detent than it is the lockbar tension.  On the bright side, the problem does seem to subside with continued use/wear.  My first generation ZT 0550 was very difficult to open when new, but has the detent ball has worn in, knife has become much easier to open.  The Gen 2 model was, if anything, even more stubborn than the first to open when I received it.  But it’s slowly becoming easier with repeated openings – this break in process does take a while.

The main complaint with the first generation ZT 0550 pocket clip (as I pointed out in my original review) was that it was the same one that Kershaw (parent company of Zero Tolerance) puts on several of their cheaper knives.  So when ZT made the 0560/61, (bigger brother to the ZT 0550) they designed a new pocket clip which is more aesthetically pleasing and better functioning in many respects.  It didn’t take much of a change to the ZT 0550 (basically the holes where the new pocket clip is attached to the knife are aligned vertically instead of horizontally.

ZT GEN 1.5?

Initially when ZT began shipping the updated versions of the ZT 0550, folks noticed that while the titanium backside was updated, the front (G10) side was not because the pocket clip holes corresponded to the first generation pocket clip.  The Gen 2 model I received was consistent with this hybrid “Gen 1.5” configuration.  For the time being, the Gen 1.5 configuration is the most flexible one to have if you’re interested in changing out the G10 scale to something other than the widely panned black G10 one which comes from the factory.  This is a key issue for me – right now I own two accessory G10 scales (as seen in the above photo – one blue/black, and one brown).

As of this writing there are virtually no accessory ZT 0550 scales available on the market, outside of some made by smaller customer operations.  Supposedly Hinderer Knives (Hinderer designed the ZT 0550 in collaboration with Zero Tolerance) is going to make more accessory scales.  Unfortunately, Hinderer is rather cagey on the details of when we’ll seem them, or the accessory stand offs he’s supposedly going to manufacture as well.  Will any more accessory scales be made for the first generation ZT 0550 be made?  When will Gen 2 configuration scales make it to the market?  In order to be prepared for these uncertainties, I contacted Zero Tolerance and determined that if you have a Gen 2 titanium backside, you need only get the steel liner which corresponds to the scale configuration you want to use (both generation steel liners will mount to the Gen 2 titanium side).  So I requested a Gen 2 steel liner, and they also sent along the factory standard black G10 scale in Gen 2 pocket clip screw hole configuration:

The ZT 0550 appears to be a knife which Zero Tolerance is committed to keeping in their catalog for a long time to come.  Hopefully ZT will continue to update and enhance the ZT 0550 (particularly the detent) because  I do like it, and it’s tough to beat for the money.  As of this writing, there’s plenty of new first generation ZT 0550 examples out there, which can be picked up at bargain prices –  expect to pay more for Gen 2 examples.  Which one to get?  Besides the desirable improvements, the Gen 2 models will be your best bet if you want to ensure you can get accessory scales for it.  At some point (if not already) no additional accessory scales will be made in the first generation pocket clip configuration – so finding scales for the first generation models will only become more difficult as time passes.

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