i was decocking and.......WTF !!!

[Drew]

A couple things...

First, I didn't like the look of the original rope on the cocker so I replaced it with 5mm yellow kernmantle climbing rope. This type of rope is to be used in carabiners and tie offs, etc. it is made to be more abrasion and shock resistant.The yellow is more visible if you drop it in the woods too. Amsteel would work well also. Personally I inspect the rope and hooks regularly

Secondly, I've noticed two things about the hooks.
1) the drift pins that hold the brass rollers in place can "travel". i've had to use a punch and hammer to "re-center" mine several times. I try to make the pins, which are subflush on each side equally subflush.

2) Most of us use the hooks the same way everytime ( I assume), be it hooks up or down. Personally I do hooks up. But I've noticed that the hooks themselves are getting a groove/notch/dent on the inside where they rub along the rail during cocking. This creates a stress riser, a location for a crack to propagate from.

I've only had this rope cocker a year and I am thinking about replacing it. Plastic fatigues over time with the kind of loads we are talking about so perhaps this should be a standard practice. For the price of a hunting arrow it could prevent serious damage. Just my thoughts...

[nyexhunter]

and as nyexhunter said,

"You may be on to something with your theory.
My matrix had a ridge in the middle of the groove where the rope cocker goes. It looks like that is where two sides of the stock were put together. The ridge looked like it would be sharp against the rope so I sanded it down to make it smooth. It took the camo paint off as well, however, having a small bit of white in this spot is no big deal to me.nyexhunter"

I looked at that area and I do have a protrusion in the groove
located in the center.

maybe that's the culprit....

Please take a look at your crossbows at the grooved area behind the safety where the rope cocker sits. There was a defininte ridge, protrusion, or whatever you want to call it on my crossbow.. I think that with 200 or more #s of pressure over time this could have a knife like effect on your rope. I sanded this area down with some light sand paper until all signs of this ridge was gone and this area was totally smooth.

The paint in this area is gone and it is bone white there now; which for those into looks, is not attractive, however, it does not bother me. In fact, I can plainly see where to put the rope and it is smooth and will not wear my rope over time.

[Pydpiper]

I see a good market for some Titanium hooks and a Kevlar rope.
Aluminum would work, but not as much cool factor.

[amythntr]

...I am going to check out our 380's and make sure all appears well and there are no issues...I agree with changing the cocking rope every couple of years or so just to be safe...heck...we lose a bunch of stuff each year and don't think twice about replacing it!

Anthony

[gendoc]

That is very odd. We get very few issues with rope cocking aids and I have been uncocking 405's with no issues. If you could send us the rope and hook I will send you a new unit. I want to take a look at the hook and the rope to see why they failed.

Peter

I just bought a new factory cocking aid for less than shipping with insurance,
than sending mine back to you.
plus I don't have to wait !!!
I guess it will be a mystery why this happened....until something else fails, then you will get the complete package back.
thanks for your interest.

[munch]

my buddy was over today and says he had the very same thing happen to him on his 380. looks like the rope broke first

[wabi]

Could the one that failed be sent to Danny Miller?
Be interesting to see if the experts can figure out what happened & why it failed.

[foofoo]

thought this was interseting. friction can cut good on its own. https://www.youtube.com/watch?v=IShghbDZMlo

[gendoc]

Could the one that failed be sent to Danny Miller?
Be interesting to see if the experts can figure out what happened & why it failed.

i'll be glad to send it to danny miller !!!
and let him do forensics.....and I think I will
thanks wabi and hey munch, I hate that it happened again....
but i'm kinda glad its showing up.
this problem needs attention.
the rope cocker was bought when I got the 380 last year.
I have used the same style RC with all my Excalibur CB's
for years...and never had any problems.
the extreme pressures might need some research.

as others have said, the 405's use the same RC.....
lets see whats the deal next year.............

great info foofoo !!!

and too all you other folks that have not experienced any problems..
I hope you don't have the failure and possible damage I have.
maybe yours are bullet proof, I hope it stays that way..........

[colouredchameleon]

May I suggest that the lenght rope be measured from the T handles to the ruptured end. Then mark the same point on a new one then slowly decock your crossbow as before. Note any surfaces the measured mark may come in contact.

Scope Base / Arrow Retainer etc.

NOTE the directional force of the string combine with the direction of pull / release while decocking can be quite different depending on whether hooks are up versus down.
The force applied at the hooks on the string when pointing down tends to be towards the rail. Where as Hooks Up it could be possible to lift the string off the rail and if at a extreme enough angle could increase the possibility of upper hand side hook jumping the rail which if it occurs early in the decocking phases result in contact with the scope mount or sharp edge of arrow retainer..

[gendoc]

May I suggest that the lenght rope be measured from the T handles to the ruptured end. Then mark the same point on a new one then slowly decock your crossbow as before. Note any surfaces the measured mark may come in contact.

Scope Base / Arrow Retainer etc.

NOTE the directional force of the string combine with the direction of pull / release while decocking can be quite different depending on whether hooks are up versus down.
The force applied at the hooks on the string when pointing down tends to be towards the rail. Where as Hooks Up it could be possible to lift the string off the rail and if at a extreme enough angle could increase the possibility of upper hand side hook jumping the rail which if it occurs early in the decocking phases result in contact with the scope mount or sharp edge of arrow retainer..

thanks for your thoughts......but, this was done right after the SHTF
it appears to be in the area between the right side string groove
and the right hook.
that kinda limits out the scope mount. and, as I know it was not that.
I was looking at the area when it failed. just want to know why and
what else did it damage.
I don't want a delayed action failure down the road.
these fine bows cost too much for me to replace at will.

[colouredchameleon]

Hear ya.
Agreed.
Would be the same!
If you just would have gotten a 405 you would have avoided this dilemma altogeither.

[xcaliber]

Well, my scope base came loose today on the 355. I swapped out scopes, and put the Redfield Revenge on ole Trixxi, I locktited the button head screws when I put the Trigger Tech Trigger in, and snugged the screws pretty good I thought. The shallow hex wrench pockets stink, and it is very easy to strip these screws, so i went and got some socket heads in stainless, which provide a hex for a larger allen wrench, and you can snug them up pretty good. I decided to instal a lock, and flat washer also, and that presented a bit of an issue. The hooks when facing down will catch the heads, turn the hooks over, and viola! I liked it so much, I did the same to Exciter! Now I'm hooks up!

[the elf]

After reading all these horror stories---I checked my 355 and my old vixen for ridges at
the seam in the cocking string groove--------and both had a ridge---which is now gone.
The other bows will get done if needed at a later date. The little white spot will help in string placement.

Another timely hint !!

[amythntr]

thought this was interseting. friction can cut good on its own. https://www.youtube.com/watch?v=IShghbDZMlo

wow...very interesting!!

Anthony