I recently received the following question by email around what to do when you have almost finished your string job, and it's time to tie off the knots to complete the mains and crosses.
Hi Jonathan, thanks for your blog post on tie off knots with those animations, it made understanding them much easier. But I am wondering how to tension final mains and crosses. For example, when pulling the last cross of a one-piece stringing job, right before clamping and tying off the knot, do you advise increasing the reference tension to compensate for potential knot-related tension losses? Or should the last strings be pulled at the same tension as all the others? Alexei
Let's take a look.
Should You Increase The Tension Before Tieing a Knot?
Just like seemingly everything related to tennis and equipment, there is no right or wrong answer here.
There are two schools of thought on it and in one group sit racket stringers who think that because the outer mains or crosses rarely come in contact with the ball and are the shortest strings on the racquet, there is absolutely no reason to add tension.
In the other group, sit stringers who want as uniform tension across the entire stringbed as possible, and having loose outer mains appears to be a shoddy string job, so they increase the tension.
Some players also don't like their outermost mains and crosses to move, in which case they will force a stringer to crank up the tension on those strings to keep them in place even if they don't like to do it.
I increase the tension by around 10-15%, and the reason I do this is for two reasons:
- Most of the top stringers I have watched string rackets, spoken to, or seen on YouTube also do this. Richard Parnell, for example, ups the tension by 4 kilos (~20%) in most of his guides, and he's one of the best and innovative stringers in the world.
- Suppose you are lucky enough to ever string on a top of the line stringing machine. In that case, most of them have a knot feature button that automatically increases the tension by a set percentage over the reference tension you have been using for the racquet. There is a reason why manufacturers include this button.
What do the Stringing Associations Say?
While most of the top tournament stringers add tension before tieing a knot, the US Racquet Stringing Association (USRSA) recommends the opposite:
We do not recommend this procedure because shorter outside mains [and crosses] don’t require as much pull-tension to be as tight as longer, centre [ones]… In short, we suggest normal tensions on tie-offs, which may result in some tension loss on the outermost main (or cross). If customers complain about this string being too loose, you can explain that these strings are far away from the racquet’s sweet spot. Also, mis-hits will actually be less jarring if outer mains are not tensioned as high as the centre mains. Stringers who are intent on increasing tension on tie-offs should not go higher than 5 pounds above normal tension. The USRSA
I think this reasoning does make some sense, as there is a correlation between higher tensions and more shock delivered to the arm, so softer strings at the extremities should reduce that jarring effect if you mishit often.
What Do Most Stringers Do?
At the higher level of stringing, i.e. tournament stringers, most of them will add tension before tying off.
They can choose to do the opposite of the USRSA recommendation above because the players they are stringing for very rarely hit off centre, so any arm-friendly benefits of low tension on the outermost mains are going to be negligible.
The other belief is that looser strings at the extremities of the racquet can propagate to the centre mains, producing an inaccurately tensioned stringbed.
Based on my testing with various string tension testing tools like the MSV MiniSTT, I have not discerned any real difference between the tension on the centre mains when using both techniques.
Therefore I'm not sure how big a deal it makes. However, for the sake of leaving nothing to chance, I can see why tournament stringers decide to bump up the tension.
At the club stringer and hobby level, it is more or less 50/50 and usually depends on who taught the person to string.
What Should You Do?
If you string for yourself, my advice is to test both techniques out, pick your favourite and stick with it.
If you string for others, you should also pick one and stick to it as the key to stringing rackets, especially for others, is consistency as players will get used to your stringing technique.
However, if you choose not to add tension, some customers may complain that the last mains/crosses are looser than the centre strings, so be prepared to do it for specific clients.
I would also remind all stringers that no amount of tension added will make up for a poor quality tie off knot.
Hence, it's vital to get competent at the knot you choose, and I would prioritise knot perfection over adding tension onto the outer strings.
For those who still can't decide, my preference is to add between 3kg-4kg of tension before the tie off. That is what I see the best stringers doing, and as a home stringer, it makes sense to copy those who do it for a living on tour.
What is your preferred choice? Bumping up the tension on the last main, or do you leave it as is? Let me know in the comments.