A question for long term Zero Tolerance owners.

T

TheEdge01

Joined
Apr 3, 2015
Messages
3,707
Hey guys, I recently bought my first Zero Tolerance, a 0566 Black Wash. I am just curious about how well the torsion bar holds up. Zero Tolerance says they test them up to 10000 openings. Should I just have it replaced every so often or wait until it breaks? I prefer to keep it assisted. How long have you guys went without having to replace your torsion bar?
 
I own a ZT0350 for 7 years and never had any issue with the torsion bar so far
 
I think it just depends. Some seem to last forever while others seem to break after not much use.

If you are worried about it go to the ZT website and they have a warranty form you can fill out and request basic parts and order a torsion bar to have on hand if it ever breaks. I wouldn't worry about replacing it if it's still working fine and would wait for a problem. More than likely you will never have an issue unless it's your only knife that you plan on using frequently for many years.

I think you are probably over thinking it but it can't hurt to have a spare on hand for peace of mind.
 
open it up and add grease if it doesnt already have some (usually it will rattle and you can hear it, if it doesn't have any). I've heard this break a lot in kershaws.. zt also has redesigned the tension bars through the years, I assume to improve on its design to reduce those issues.

either way my 0770cf hasn't broken.

also like said above... zt's warranty is great. they will send you another tension bar for you to install or send it to them and they will fix it.
 
Last edited:
FlaMtnBkr said:
I think it just depends. Some seem to last forever while others seem to break after not much use.

If you are worried about it go to the ZT website and they have a warranty form you can fill out and request basic parts and order a torsion bar to have on hand if it ever breaks. I wouldn't worry about replacing it if it's still working fine and would wait for a problem. More than likely you will never have an issue unless it's your only knife that you plan on using frequently for many years.

I think you are probably over thinking it but it can't hurt to have a spare on hand for peace of mind.
Click to expand...

Benchmades customer service dept told me to send my knife in every few months to have the Omega Springs replaced. I didn't know if ZT's torsion bar should be handled in a similar way. I will try to get in touch with ZT to request a spare one.
 
TheEdge01 said:
Benchmades customer service dept told me to send my knife in every few months to have the Omega Springs replaced.
Click to expand...

!!! Wow!!! First I've ever heard anyone say this. Still a noob to BM, though.
 
I played with my ZT 0566BW a lot so I went through a few torsion bars in a year. You can order torsion bars online, ZT will send you multiple per order and shipping is free. So for me it was a no big deal, just always had a few laying around.
 
IMHO, the torsion spring design used by ZT and Kershaw is hugely flawed. I have been through 6 springs in my ZT0566 in less than a year. Imagine if any spring in your car failed this many times in a year. I would hazard a guess that nobody at ZT nor Kershaw have engineering experience with springs.
 
Aldebaran said:
I would hazard a guess that nobody at ZT nor Kershaw have engineering experience with springs.
Click to expand...

And I would hazard that you have no idea what you're talking about. Kershaw/ZT Speedsafe technology was pretty much invented by custom knifemaker Ken Onion.

Would you like to tell ol' Ken that he has no engineering experience with springs? ;)

KAI USA tests their torsion bars to last up to a certain amount of openings. Some don't hit that mark before breaking; some far exceed it. That's just the nature of the beast. At least Kershaw will send you replacements free of charge, as well as body screws, pocket clips, etc.
 
Aldebaran said:
IMHO, the torsion spring design used by ZT and Kershaw is hugely flawed. I have been through 6 springs in my ZT0566 in less than a year. Imagine if any spring in your car failed this many times in a year. I would hazard a guess that nobody at ZT nor Kershaw have engineering experience with springs.
Click to expand...

6 in a year. Not sure about that one. I've yet to see one fail under my experience, let alone 6.
The plus side is that if it does break, it will be de-assisted as I much prefer anyways.
 
Remove it and Polish the washers with 2500 grit automotive sandpaper. It makes a world of difference. I actually miss mine
 
I have had a ZT0566 for about a year and a half. When I first got it I opened and closed it a lot (for about the first month) because it was pretty stiff and needed breaking in. Since then, I only open it when I need to cut something with it, which isn't all that often, but it does get used. No problems with the knife or the torsion bar. It works fine. It may break tomorrow, but so far, so good.
 
I have several ZTs and the only issue I've had was with a pocket clip. I contacted kai-USA and received a replacement in the mail promptly. If you're concerned about the torsion bar breaking I would send them an email asking about a spare.
 
Yeah I will agree that ZT has one of the best customer service /wartanties in the market, I've used it a handful of times and never been disappointed.
 
TheEdge01 said:
Benchmades customer service dept told me to send my knife in every few months to have the Omega Springs replaced. I didn't know if ZT's torsion bar should be handled in a similar way. I will try to get in touch with ZT to request a spare one.
Click to expand...

The Omega spring replacement every few months seems a little extreme to me. I have knives with Axis locks that are older than some of the people on this forum and they have original springs. I've had a couple of knives with not a lot of kick on the torsion spring, so I got replacements. After that, I had zero issues. I would make it a practice to send my knife in unless it needed a lot of work.
 
Not a big fan of assisted opening. I see the main reason folks still buy ZT 0566/0566cf is maybe the size? Anyway, had a kershaw with AO and the torsion bar broke within the first two months. KAI did sent me two replacements promptly.

I don't have enough experience but somehow I feel the Omega springs on Axis lock are much more durable (meaning lasting much longer) that the AO torsion bars.
 
my oldest assisted ZT/kershaw is my 6 year old ZT350, never had an issue with the spring. If you are breaking 6 per year, it's something you are doing.
 
grownstar said:
And I would hazard that you have no idea what you're talking about. Kershaw/ZT Speedsafe technology was pretty much invented by custom knifemaker Ken Onion.

Would you like to tell ol' Ken that he has no engineering experience with springs? ;)

KAI USA tests their torsion bars to last up to a certain amount of openings. Some don't hit that mark before breaking; some far exceed it. That's just the nature of the beast. At least Kershaw will send you replacements free of charge, as well as body screws, pocket clips, etc.
Click to expand...

A technology being invented by someone does not imply that they have properly engineered the invention. Something might work well enough without any real knowledge of how it works. I am not disparaging Mr. Onion. He is a very talented designer and knife maker. The fact that the springs break at different rates is evidence that they are not engineered correctly or that the QC on the production of the springs is very poor.

I am not an engineer but I have had some experience in designing springs and experience with failure modes. The spring in the ZT0566 is being asked to work in a way that most spring design guidelines would recommend against IMHO.

Also you are right, KAI has great customer service and they send me springs free to South America without even questioning me. KAI is a great company and I have no complaint about them at all.
 
I just got my little care package from KAI yesterday, I asked for just about everything under the sun since if they were going to send me some screws, might as well get them to send me a new torsion bar, pivot assembly, so forth. I'd suggest that you just contact KAI to send you a torsion bar as well, that way if it does break, you have one on hand and don't have to wait a week or two.

On my 0566cf I started having some rattling issues with the torsion bar, so I just took it out. I personally didn't like it deassisted, I had to loosen the pivot too much, which in turn caused more blade play than I was comfortable with. Other then that, the torsion bar hasn't caused problems at all. Super, super easy to fix yourself if it does break.

I would also try to keep it greased, that makes a big difference. I cleaned out all the crap KAI put in it and I just used some Militec-1 I had laying around instead. It fixed the rattling, as well as made it smoother.
 
You must log in or register to reply here.
Back
Top