Crossbow Nation banner

1 - 9 of 9 Posts

·
Registered
Joined
·
480 Posts
Discussion Starter · #1 ·
I need some thoughts and suggestions about what you might do.

I have a second crossbow: a 155# Jandao compound. I had wanted to experience compounds without the expense, as I primarily prefer recurves.

Two summers ago, one of its half-moon nocks shattered, the shot sounded like a .44Mag, my arrow lay FUBAR about 12 yds from my crossbow and the strings and cables were no longer in their furrows.

I built myself a press out of bits and bobs, compressed the limbs and removed the cables.

The cables and string have damage to the serving, but I can't tell if there is damage to the string fibres beneath. The cams have a little deformation on the edge at one spot.

All this is pictured below.

196379

196380

Cables and cable serving close-up

196381

String loop serving damage

196382

Signs of metal stress on the cam (same on both)
IMG_4066.jpeg

Slightly bent lip to the string groove (same on both cams)

What I need from the CBN experts is an assessment of what is salvageable and what is not.
Options for the string include:
  • Buying new strings and cables (expensive for that model).
  • Being a "chinese" bow, a lot of stuff is made in the same place and rebranded so I could look around for a bow that looks like mine from some of the known incarnations (typically cheaper) and hope they fit.
  • I could try to make my own strings and cables, despite having never done so before
  • Any other options overlooked?

Cams are no longer made for that model, so if the cams are not salvageable:
  • Buy cams from a similar bow and hope.
  • Keep the ones I have an hope.
  • Convert it to a "recurve" by getting a shorter string an just looping it to the cam pins on a spacer like a Koda bow.
  • Any other options overlooked?
Seems a shame to bin a bow that is otherwise fun to target shoot with.
Thoughts?
 

·
Member
Joined
·
3,622 Posts
I would not try to use the damaged string and cables. It’s not worth it. With the state the bow is in, I would take the axles out and roll them on a smooth surface (countertop or piece of glass) to see if they are bent from the dry fire. Take a cotton ball over the limbs to look for splinters. The cams, IMO, may be salvageable. If the bearings are good, and there is only slight bending of the string groove, you may be able to carefully bend the lip back, then file/sand to make sure there are no sharp edges to cut serving and string. If you try to make a ”recurve” out of the limbs and axles, I believe you will be shocked at the draw weight, in addition to pulling the limbs way beyond their designed flex limit.
 

·
Registered
Joined
·
480 Posts
Discussion Starter · #3 ·
I would not try to use the damaged string and cables. It’s not worth it. With the state the bow is in, I would take the axles out and roll them on a smooth surface (countertop or piece of glass) to see if they are bent from the dry fire. Take a cotton ball over the limbs to look for splinters. The cams, IMO, may be salvageable. If the bearings are good, and there is only slight bending of the string groove, you may be able to carefully bend the lip back, then file/sand to make sure there are no sharp edges to cut serving and string. If you try to make a ”recurve” out of the limbs and axles, I believe you will be shocked at the draw weight, in addition to pulling the limbs way beyond their designed flex limit.
I'll certainly look at the cams and limbs as described. I know the edges are smooth and the outward curvature is only slight.

Regarding the "recurve" route:
Is the draw weigh difference going to be down to the lack of let-off? With a 185lb Koda', I'm used to that.

And regarding the flex limit: if I buy or produce a string of my own that recreates the original axle-to-axle width of the bow at rest, and the barrel it is pulled along is the same, ie the power stroke is the same, would that not mean the limb flex remains the same?

Is there something about cams that means the limbs move less than a recurve for the same power-stroke?
 

·
Registered
Joined
·
9,709 Posts
I would not try to use the damaged string and cables. It’s not worth it. With the state the bow is in, I would take the axles out and roll them on a smooth surface (countertop or piece of glass) to see if they are bent from the dry fire. Take a cotton ball over the limbs to look for splinters. The cams, IMO, may be salvageable. If the bearings are good, and there is only slight bending of the string groove, you may be able to carefully bend the lip back, then file/sand to make sure there are no sharp edges to cut serving and string. If you try to make a ”recurve” out of the limbs and axles, I believe you will be shocked at the draw weight, in addition to pulling the limbs way beyond their designed flex limit.
X2. If the axles and limbs are good a string/cable replacement or reserve should be all you need. Good luck with it.
 

·
Member
Joined
·
3,622 Posts
Cams let out much more string than the cam lobes take up in moving the limbs together. That’s how the cams have mechanical advantage. If you would hook up a string to the axles of a, say 175# compound crossbow, the draw weight could easily be 3-400#. The limb would move much farther than intended. Several years ago, out of curiosity, I set up a crossbow with limbs from a 70#, single cam vertical compound. I used simple idler wheels, not even a direct hook up. The draw weight of those 70# limbs, in that configuration, exceeded 270#.
 

·
Registered
Joined
·
480 Posts
Discussion Starter · #6 ·
Cams let out much more string than the cam lobes take up in moving the limbs together. That’s how the cams have mechanical advantage. If you would hook up a string to the axles of a, say 175# compound crossbow, the draw weight could easily be 3-400#. The limb would move much farther than intended. Several years ago, out of curiosity, I set up a crossbow with limbs from a 70#, single cam vertical compound. I used simple idler wheels, not even a direct hook up. The draw weight of those 70# limbs, in that configuration, exceeded 270#.
Riiiiight.... Yeah, that sounds pretty unmanageable

My back complains drawing my 185 Koda Express. A retrofitted compound to recurve would probably leave me bed ridden for the rest of the month.
 

·
Registered
Joined
·
3,681 Posts
I would get a new bow. It isnt worth waiting any money on to later have a problem from the dry fire. Good luck
 

·
Registered
Joined
·
270 Posts
im so glad i saw this, checked my cams, they are busted even worse than this, thank you very much
 
1 - 9 of 9 Posts
Top