Racket Flex and String Tension Preference

Many users of very flexible frames like to string very tight. 

The most common reason was to improve accuracy and that they enjoyed the feel of the racket flex. When strung at normal tensions, these folks claimed the frame stopped flexing.

Out of curiousity, my friends and I tried stringing some very flexy frames (RA 50s) to investigate the flex response.

Tight (75 lbs)
Both the full poly and the full synthetic gut felt like a board. 

The stringbed was so stiff and tight we did not feel any string pocketing at all. 

However, impacts did not feel harsh as we could clearly feel the racket flexing on impact. 

Contrary to the beliefs about stringing it tight for greater accuracy, all our shots suffered some loss of directional control. Some forehands leaked to the right and backhands leaked left. It felt like our timings were slightly late and off.

We tried "swinging" the racket and "arming" the racket. (link) Well connected sweetspot hits felt nicer but it was still boardy, extremely low powered and inaccurate.

Neither could we generate any decent spin. Not even slices.

Serves were pathetic. No power, no pace, no spin, no height and plenty of double faults!


Normal (55 lbs)
This was near our usual tensions so everything felt familiar.

It was comfortable, spinny, accurate although still a tad low powered.

It was interesting to note that when we had sufficient time to prepare, step into the shot before "swinging" the frame, there was a very powerful delivery. The string and racket flex worked in unison.

Even when we were late, on the run and half-muscling through the shot, we were able to partially load the strings before flexing the racket.

After hitting with this, we discovered what and why we did not like about the racket flex earlier with the tight tension. 

Whenever it flexed, power was absorbed by the frame. The energy that was incoming from the ball, and the energy which we threw into the forward swing, was heavily dissipated by the racket flex. 

And before the flex could rebound, the ball has left the strings. Hence the very low power and poor directional control.

Swinging worked much better.


Loose (35 lbs)
For this tension, we chose a stiff poly string and strung it full bed.

The first thing we noticed was the extra huge sweetspot. It was so forgiving we thought we were using an oversized racket!

The second thing that impressed us was the abundance of power and spin. A huge increase over the normal tension.

Along with this was the ability to load and pocket the strings. With the added advantage that the harshness of any off-centred shots would be safely cushioned by the racket flex.

At this tension, the usual downsides were the high rebound angle of the stringbed and some light string buzzing. However, this had nothing to do with the racket flex. It was a common problem across all types of racket frames.

Most distinctly, we did not feel much of the racket flex.


Conclusion
Among the three, we preferred the one lowest tensioned. 

However, for practical play, mainly to mitigate the high rebound angle, we would string somewhere around the mid-40s lbs, depending on strings.

What we unanimously agreed was:
(1) flexible frames felt superior to very stiff frames,
(2) flexible frames are very demanding to wield properly, and
(3) stringing flexible frames loosely made them much easier to use for recreational players as it was much better to load the strings than to flex the racket.




     

Measuring String Left in Reel

Most who favour a particular brand of strings end up buying reels. 

However, many of my friends still get caught not knowing how much string there is left in the reel.

Depending on the brand, gauge and type of string, the more common strings weigh between 15 grams to 20 grams per set of 40 ft. It is easy to use weight as a proxy to estimate how much string there is left.

Below is a partially used reel of poly a friend handed to me. It weighs 331 grams.

He wanted 3 rackets strung with full poly, so I cut out 3 sets of 40 ft each, total 120 ft of string from the reel.

That left me with 275 grams.

The simple calculations that follow:

120 ft of string weighs 56 grams (331-275)

Each set of 40 ft weighs ~19 grams (56/3)

This full reel of strings only should weigh ~308 grams (56/120 x 660)

So when you next buy a new reel, measure and record the weight of the entire reel before using it. You will have a better idea how much string there is left.