Testing the Pro Stringer Portable Stringing Machine

Professional stringing is all about accuracy and consistency. The strings need to be installed in the racket at the desired tension, and that needs to be repeated racket after racket after racket. This allows players to have confidence that when they hit the ball, they will get the result they expect over and over and over.

Professional tennis players must contend with different stringers and stringing machines every week, introducing some natural variation into the consistency/accuracy equation. But the differences are magnified because some of the stringers on tour use questionable techniques and some of the machines pull questionable tensions.

This is especially true of – though not limited to – the lower levels of professional tennis. It is a sort of insult to injury situation when players are not even earning enough to cover their expenses and are receiving inaccurate and/or inconsistent for their hard earned money.

So, even though I get paid as an “on site” stringer at professional tournaments, I completely understand why some players would look for a better, more affordable “off site” option. As I noted in a previous post, Rubin Statham and his brother spent some $17,000 on stringing in their first year on tour, and found the quality of stringing, especially in Asia, abysmal (my term, not his).

Statham’s need for good quality, consistent, and affordable stringing led him to design and bring to market the Pro Stringer Platinum, a 4 pound, electronic, constant pull stringing machine that fits in a small travel bag.


I was fortunate to meet Statham at the ITF Pro Circuit Winston-Salem Futures last month and he was nice enough to allow me to test his machine.

The package consists of a swiveling mount that attaches to a table top, a tensioner, two flying clamps, and a power supply that is convertible to be used anywhere in the world.


The Pro Stringer is easy to set up and get the frame mounted on. Because it clamps to a table top, I actually ended up stringing the racket sitting down because it was too low to stand up and use. This took a bit of getting used to, but could also be a benefit for the player stringing their own rackets at the end of a long day.

The two point mounting system held the racket securely. For most professional stringers a 6 point mounting system is preferred to reduce stress on the frame, but let’s not forget that the Prince Neos has been used to string millions of rackets over the years with a two point mounting system.


Rubin Statham demonstrating how to mount the frame using my Pacific X Feel Tour

My test racket was one I have strung many times in the past year on both my Babolat Star 5 and Wilson Baiardo machines: A Wilson Pro Staff 97 RF with Pacific X Cite 1.25mm string at 55 pounds. I have a good idea what the stringbed should feel like after installation: 39 units of dynamic tension measured using an ERT 300 tennis computer.

I first used my scale to test the calibration of the Pro Stringer’s tensioner. I found that it initially pulled to the 55 pounds reference tension, but then quickly feel back to 50 pounds. That is not optimal, but if it consistently pulls to 50 pounds when set at 55 pounds reference tension (which it seems to do), then I could easily adjust for that.


A unique aspect of the Pro Stringer is that you move the tensioning unit itself, setting it up against the frame and then running the string into the rotary tension head and pressing the tension button. Because the tensioning unit has to be as tall as the racket, the Pro Stinger has only 180 degree not 360 rotation (like the Prince Neos and unlike the Star 5 and Baiardo). So, I had to get used to swinging the racket back and forth to string. Statham also showed me how to make the process faster by not only swinging the racket but also tilting and moving the tensioning unit at the same time. With some practice, I think that would really speed up the process.

Using my own starting clamp in addition to the supplied flying clamps I was able to install the mains in just under 9 minutes. I never use flying clamps so this was a bit cumbersome for me but I got better with them as I went.

Stringing the crosses also took longer than normal (about 15 minutes) because of the need to set the tensioning unit against the frame and also because the cross-beam on which the frame mounts sit is so close to the string bed. There is less than an inch of clearance so you have to weave to the middle of the frame and then make an awkward (for me) transition through the middle mains and then you can continue onto the other side of the frame.


I practiced once on the machine with my Pacific X Feel Tour before doing my test

I took a couple of additional minutes to tie off the crosses and use my setting awl to straighten the strings, both of which were harder because the frame mount is naturally not as sturdy as on a 150 pound machine.

In the end, the dynamic tension of the stringbed as measured by the ERT 300 was 31. Although the conversion from DT to pounds of tension is not perfect, the DT of 31 suggests that the stringbed came out about 10 pounds looser on the Pro Stringer than on the Star 5 or Baiardo. As already noted, about 5 pounds of this was due to the tensioner’s calibration being off. The other 5 pounds was likely due to the quality of and my clumsiness with the flying clamps.

Overall, I liked the Pro Stringer a lot. It does what it does – provides players with a portable electronic, constant pull stringing machine — as well as any machine I know. At a cost of US$790, it will easily pay for itself in a year’s time or less for a serious professional who restrings as often as they should. If I played tennis for money and had to travel a lot I would definitely get one. It’s also a good option for traveling junior tennis players as well as underfunded college teams.

That said, there are a number of improvements I would like to see to the Pro Stringer. Setting the tension on the machine uses an analog dial (like the Neos) rather than a digital display (like the Star 5/Baiardo). That was tough to use with my old, bad eyesight. Better clamps would be great – something like the well-regarded Stringway flying clamp. More room between the cross brace and the frame would be very helpful with weaving the crosses. There is no table lock, so I don’t know how hard it would be to string a Prince O Port racket. I guess you would use the banana/boomerang tool, but I have never had to do that with my other machines’ table locks. Non-essential but convenient options on the tensioning unit would be a pre-stretch option and a knot over-tension option. We use those frequently during ATP Tour events.

I don’t know the status of the project, but in discussing these issues with Statham he indicated that a new version of the Pro Stringer is in production which will incorporate many of these changes. I look forward to giving the new model a try when it is available.

String Loose! Examining String Tensions at Pro Circuit $25K Winston-Salem Futures

For various reasons I hope to write about in the future, most amateur players string their rackets too tight.

Last year I reported that the average tension for the rackets I strung at the NCAA tournament and the Winston-Salem Futures was 53 pounds, compared to 55.5 pounds for my regular customers in 2015 (who I have worked with to string looser).

Machine at WS Futures

Of course, there is no single “correct” tension for any particular string, racket, or player — or combination thereof.The loosest racket I strung at the 2016 Winston-Salem Futures was 40 pounds (Dennis Nevolo) and the tightest was 28.5 kilos (62.7 pounds) with a 10% prestretch of the monofilament string (Stefan Frljanic).

Still, it is worth noting that the average string tension at the 2016 Winston-Salem Futures was down 2 pounds from last year to 51 pounds! Only 2 players strung in the 60s, while 15 strung in the 40s.

My regular customers are down from 55.5 to 54.2 so far this year, so hopefully my “String Loose” campaign will continue to take hold among recreational players as the loose stringing trend has among professionals.

Stencil at WS Futures

String Tensions at ITF Pro Circuit $15K Futures of Winston-Salem

For various reasons I hope to write about in the future, most amateur players string their rackets too tight. As noted previously, the average string tension for the rackets I strung at the NCAA tournament last month was 53.3 pounds.

Of course, there is no single “correct” tension for any particular string, racket, or player — or combination thereof. As at the NCAAs, at the ITF Pro Circuit Futures of Winston-Salem I saw a 20 pound range from the loosest strung racket (42 pounds) to the tightest (62 pounds).

Burn from Futures WS

But looking at the average string tension over a large number of rackets can be instructive. So, I was interested to find the following for the string tensions I recorded at the Futures of Winston-Salem:

  • Mean = 52.94
  • Median = 53

This is very close to the 53.3 pound average tension I recorded for the rackets I did at the NCAA tournament.

I estimate that this 53 pound average is about 5 pounds looser than the average string tension for my amateur customers, even those who use all monofilament strings.

String loose people!


Stringing Report from 2015 NCAA Division 1 Tennis Championships

As noted previously (here and here), I recently spent 2 weeks as one of the official on-site stringers for the NCAA tennis tournament at Baylor University in Waco, Texas. Although we had some competition from off-site stringers who aggressively solicited business away from us, the four members of the MOZI Tennis team still strung several hundred rackets. This included the women’s doubles champions from Alabama, and the men’s singles, women’s singles, and men’s doubles finalists (from Wake Forest, Stanford, and Texas).

Selfie delivering rackets to the NCAA men's singles finalist

Selfie delivering rackets to the NCAA men’s singles finalist

I personally worked on rackets for 49 different players from 27 teams. This included 18 women from 12 teams and 31 men from 15 teams. Although this is not a random sample of all players in the tournament, it is a fairly diverse group of players.

For these 49 rackets, the string tensions I observed were:

  • Overall: 43 pounds to 63 pounds
  • Men: 43 pounds to 59 pounds
  • Women: 46 pounds to 63 pounds
  • Overall average: 53.3 pounds
  • Men’s average: 52.25 pounds
  • Women’s average: 55.2 pounds

I find it interesting that even though men can generate more power on their own than women, women tend to string tighter than men. Part of this may be due to women generally using more open string patterns than men, but it is also the case that each player develops their own feeling for the optimal string tension for their particular racket and game. To wit: the highest recorded tension in our stringing room was 69 pound mains and 68 pound crosses.

Head Speed with RPM

Almost all of the players, men and women, used all polyester monofilament strings – 44 of 49 players. 4 players used hybrid stringing (monofilament mains and synthetic gut/multifilament crosses), and 1 player used all multifilament string.

A few string brands were most common:

  1. Luxilon – 31%
  2. Solinco – 20%
  3. Babolat – 16%
  4. Pacific – 12%
  5. Wilson – 6%
  6. Prince, Tecnifibre – 4%
  7. Head, Kirschbaum, Pros Pro – 2%

Pacific was overrepresented because I strung all of the rackets for Wake Forest men’s tennis team which has an agreement with Pacific.

NCAA Rackets

Racket brands are even more concentrated than string brands:

  1. Babolat – 41%
  2. Wilson – 29%
  3. Head – 24%
  4. Dunlop, Prince, Tecnifibre – 2%

An amazing 94% of players used one of three brands.

Stringing in Athens, Georgia

Tournament stringing is unpredictable. That is the fun and the challenge. One moment you are sitting outside enjoying beautiful weather and a gyro, the next moment you are at the tennis courts picking up rackets because you got the call from the coach that their practice is ending soon.

Today was my first day stringing in Athens, Georgia. I am excited to be part of the Game Set Match Tennis stringing team again. This is the second time I am stringing for Jay Lewandowski the owner of Game Set Match Tennis, the first time being in 2010 (read more about that trip).

Game Set Match Tennis is not the official stringer for the NCAA Division 1 men’s and women’s tennis tournament, but many of its clients qualified for the tournament.

The first matches for the women are on Thursday the 17th and for the men Friday the 18th, but we already had 29 rackets come in today. Hopefully business will be strong through Saturday and the teams for which we are string do well in R1.

Early racket and string info from the 15 rackets I did today:

  • Rackets: Head (6), Wilson (5), Babolat (3), Prince (1)
  • String:  Babolat RPM, Luxilon Alu Power Rough, Technifibre Ruff Code, Tecnifibre Black Code, Tecnifibre NRG2, Wilson NXT, Babolat Pro Hurricane Tour, Babolat VS Gut
  • Stringing: Hybrids = 9, All poly = 6
  • Tensions: Average = 52 (median of 49, 49, 50, 52, 52, 52, 52, 59, 59, 60, 60, 60, 62, 62, 62).

Hopefully as we get busier I will have time to send out reports on our work.