By Robert Martin

(August 18, 2011) Last year, Babolat celebrated their 135 year anniversary in the tennis world, and it is still incredible that with regards to their VS natural gut string, little has changed over the years.

For the most part, in 135 years of string progression, the only changes to Babolat VS Natural Gut has been the utilization of newer protective coatings. That has finally changed with the newest iteration, but is it a positive change to alter the structural formation of one of the most popular strings?

First I wanted to understand what exactly the structural change was, because I was skeptical of the ThermoGut coating that was applied in the previous change. It turned out that it was not a drastic change, as the standard practice before was to apply a coating of "Babol All-Season Coating" periodically to protect against fraying and adverse weather such as humidity and moisture.

ThermoGut was an advancement of this coating that was applied at the factory for more consistent and sure application, but the newest BT7 natural gut actually reduces the number of individual intestinal fibers that are used in each string. In the past, it has been 14 fibers that would make up each individual string, but Babolat has found a way to process strands that are double in size, thus requiring only seven fibers, hence the name, BT7.

This new construction method is designed to drastically increase durability, tension maintenance, and resistance to humidity. So as a long-time fan of natural gut, I had to test out this new version and compare it against the previous ThermoGut VS Touch. The BT7 string is available in both natural and black colors, but I chose to limit the number of variables involved, opting for the natural.

Disclaimer: My current setup is the Yonex RDiS200 320g strung at 28/26kg with Tecnifibre X-One Biphase 1.24mm and Yonex Poly Tour Pro 1.25mm. The Babolat VS Touch BT7 was strung at the same tension on a Wilson Baiardo stringing machine.

Stringing Impressions: As expected, the natural gut exhibited the typical qualities during the stringing process, with a very slightly firmer feel to it than the previous ThermoGut. The coating was helpful in limiting friction during cross string installation, ensuring that no damage or fraying occurred.

Comfort: This was the primary category of interest because natural gut strings are typically suggested for their comfort to players with arm discomfort. While this string did not disappoint, providing a soft response, it does feel a touch stiffer than the previous version, but much softer than my current X-One/PTP.

Power: By the nature of how strings react with the ball, a softer string bed will result in greater power, and this string definitely has a noticeable gain compared to my typical setup. The sweet spot was also larger, which I appreciated for a more consistent response and easy access to spin.

Tension Maintenance: Another quality category for the BT7 string, which continues the tradition of excellent tension maintenance and long-lasting playability of natural gut string. After 12 days of intensive testing, the string did not show any appreciable loss in performance, but did begin fraying after a week and eventually broke.

Overall Comments: The VS Touch BT7 that I tested was another quality introduction in the line of Babolat strings, but I do not believe that I would necessarily call it an upgrade. This is a personal decision that each player must make on their own, as the BT7 did last longer than the previous ThermoGut used to, which would typically last eight to 10 days.

In exchange for the higher durability, was the sacrifice of some of the power, feel, and softness that makes natural gut truly special. If I were to compare VS BT7 against other natural guts like Prince Natural Gut (made by BDE), it would score favorably, but Babolat VS is more like the holy grail of strings in my opinion, and this BT7 does not quite match up.

This by no means that it is a bad string, quite the contrary. It is an excellent performing string and provides plenty of power and comfort, but when matched up against the previous ThermoGut version, it falls short based on my own preferences.

Babolat VS BT7 Natural Gut comes in a few variations, including thicknesses of 1.35mm, 1.30mm, and 1.25mm (called VS Team) available in a natural color. In addition, the 1.30mm diameter is available in a black color, as well as in a prepackaged hybrid set with Babolat RPM Blast 1.25mm.

Robert Martin is a writer for Tennis Now and has been a tennis fan and player for 10 years. He can be reached at [email protected].