Is Kevlar a stiff string on the arm?
It depends. I think the coated aramids that other companies make are stiff no matter how you string them. Ashaway Kevlar is different and if I had to guess it is because it is braided and not coated with some thick "plastic/poly/etc.
If you don't prestretch Ash Kev the string bed will deteriorate into something no one likes. Prestretching Ash Kev is important because it is braided and you need to get the braided nature of this kevlar to compress otherwise that extra space between filaments will cause a nasty loss of tension for the braided nature of the string.
Why bother with prestretching Ash Kev and move on to something else? Because once that Ash Kev is properly strung in the mains with Zyex crosses, you will have a decent stringbed for a long time.
I have prestretched it in the following ways:
1. String all the mains as tight as you dare in a "donor" racket and leave the racket sit for a day, having tied off with a bow tie so you can untie this and restring it in the mains of the primary raceket.
2. On my Neos 1000 I might triple pull mains to get some sort of prestretch, it works pretty well.
3. Secure one end then wrap the other end around a large dowel or racket handle and lean back and judiciously "bounce" on the string for some minutes. Probably the most common method.
4. I have a simple winch where I can secure one end then tie off the other end on the winch hook and then manually crank the winch. This is the sure fire way to prestretch Ash Kev. I used this method and then strung up a racket at 75lbs. Holy Crap! That string bed was stiff as a board and stayed that way. I had to cut it out.
Normally Ash Kev, once strung, will lose quite a bit of tension within the first hour off the stringer, then after an hour of hitting it will lose still more. But once that happens it settles in for a long time.
The last main on each side simply must have the reference tension increased by at least 10%, maybe 20% is better. If you don't you will be whining about the tension loss
If I used the 2 or 3X pulling or a simple body manual stretch then I would string Ash Kev no less than 65lbs on a 98-100" racket regardless of pattern. It will settle to a usable lower tension.
To prestretch or not prestretch Zyex? I have prestretched Zyex as far as it will stretch on my winch system and have strung a lot with no prestretch at all. It is easy to prestretch using the body bounce method. I secure one end, mark a reference point with a sharpie at my end so I can measure how much I have stretched it and then commence to lean back and bounce ("safety first - it is possible that you may fall for any number of reasons so be aware!)
Right now I quit prestretching Zyex and am using it fullbed in a number of rackets.
I think Zyex fullbed in a sub 60RA racket is the BOMB at 55-60lbs depending on racket and pattern.
The maddening thing about Zyex is that it can break while stringing in the weirdest place. How to avoid Zyex breakage while stringing?
1. Inspect the grommets and tube or replace with a Fittex or replace the grommet set if you note even one grommet that is cracked/split/broke.
2. Loose knots, do not cinch them up tight by hand or with clamp. The nature of the string will keep it from unraveling.
3. Moderately pull tension, build a measured slow to medium pace.
