Poly Breaks at the knot? Why?

[Icedorb217]

Okay one of my clients rackets I had just recently strung with blue gear/ OG sheep Micro came back and it was broken at the knot. He says that he had hit with it just a little and put it back in his bag and found the string at broken. The racket is a Hyper Hammer 2.7 and its tie off hole requires a long *** cross over do you think that could have been the cause of it? Anyways please help. I strung the mains at 61 and the crosses at 63

 

[drakulie]

Some reasons could be:

knots are over-tightened.

Bad grommets.

String was kinked.

Shank.

Hope this helps.

Good luck.

 

[Icedorb217]

Some reasons could be:

knots are over-tightened. - Might be the reason

Bad grommets. - They look fine

String was kinked. - Nope

Shank. - Possible

Hope this helps.

Good luck.

It did help thanks

 

[Steve Huff]

Did you use a starting knot or did you use a starting clamp and go back to tie off the top cross? 2nd, those old 2.7s haven't had grommets for awhile. A lot of the ones I string have broken and/or very brittle grommets. I have to tube a lot of holes on them. Like Drak mentioned, could easily be a bad grommet. Did you string on a dropweight. Those rotational grippers, by their nature, put kinks in the string. Could be the kink in the poly. Clamps too tight? If the break is any where near the edge of the frame, makes you think the clamps may be too tight also.

 

[diredesire]

If it's right on the knot... any chance you're tensioning the knot instead of hand tightening? A poly shouldn't experience crush damage unless you're doing something pretty extreme to it..

 

[Icedorb217]

Did you use a starting knot or did you use a starting clamp and go back to tie off the top cross? 2nd, those old 2.7s haven't had grommets for awhile. A lot of the ones I string have broken and/or very brittle grommets. I have to tube a lot of holes on them. Like Drak mentioned, could easily be a bad grommet. Did you string on a dropweight. Those rotational grippers, by their nature, put kinks in the string. Could be the kink in the poly. Clamps too tight? If the break is any where near the edge of the frame, makes you think the clamps may be too tight also.

My clamps are too tight still trying a readjust them but I still cant figure it out. It was on a dw but a klippermate and it does do damage to the string bu never to the point where it breaks.

If it's right on the knot... any chance you're tensioning the knot instead of hand tightening? A poly shouldn't experience crush damage unless you're doing something pretty extreme to it..

Hand tightened. I NEVER use my machine to tighten knots.

 

[diredesire]

You never actually mentioned which string broke, either, it was the poly for sure?

 

[SirGounder]

I think bad grommet or kinked string. Might have been alright but a couple shanks at the string snaps.