polespear bands

[So Cal Shaggy]

Do any of you tie your own pollespear bands? How do you figure out the length of the band for a polespear if you tie your own? With my guns I have a formula would that work for a polespear as well? I recently made a polespear and got some bulk polespear rubber but I do not know how long to make the band. I was thinking of measuring the length of the wishbone (the end that loops through the hole) then measure the distance from the hole in the back to where the grip is and go from there with my regular gun formula would that work?

[mnguy]

Best bet, IMO, is to do the math on how many pounds of force that rubber gives at the various % of stretch that is the ratio between length of band and distance that you want to pull it. Figure out how many pounds of force your polespear needs/wants and go from there.

Is this band for the CF spear that you made?

FWIW Aaron Crist runs about 60lbs of force on his spears, though they're really grunty and need the force to offset the mass.
http://www.spearboard.com/showpost.php?p=720155&postcount=3

[So Cal Shaggy]

Is this band for the CF spear that you made?http://www.spearboard.com/showpost.php?p=720155&postcount=3
Yeah, since it is the same length and weight of my Gat-ku I measured a new band for that spear and made a band but I wanted to make sure there was not somethihng I was missing thus loosing out on power.

[SnpperWhisperer]

The bands on my numerous spears all stretch about 2.5 to 3 times to fully cocked. of course the rubber is doubled over, so therefore the length of rubber you should cut should be:

Draw length x 2 / (either 2.5 or 3).

A draw of 1.2 metres (47 inches) requires between 0.8 metres (31 inches) and 1 metre of rubber (38 inches).

[So Cal Shaggy]

Thanks guys, I appreciate the input

[OceanEd]

It depends on how forward you want to cock your pole spear. I like to cock mine about 2/3 of the way forward when it is fully cocked.

It also depends on the band material. For more power you should go to a 1/2" band material with a small diameter hole in the center. It will give you a lot more power than the band that usually comes with your pole spear.