Babolat RPM Soft String Review

Control - Score: 74 / Power - Score: 84

In our Tennis Warehouse string lab, RPM Soft posted a stiffness score on par with the most powerful synthetic strings on the market. Not surprisingly, Chris, who typically uses stiff and low-powered polys, had some problems controlling the power. He explained, "Despite having the word 'Soft' in its name, I expected a stiffer, lower powered response from anything in the RPM family. RPM Soft played lively and offered some solid launch off the stringbed. The 18x20 string pattern of my racquet helped tame it a bit, but when hitting RPM Soft in a more powerful racquet and open string pattern, I found this string to launch the ball too much. I would have preferred this string if it stayed true to the soft feel but lowered the power level."

"RPM Soft gravitated more toward power than control," said Andrew, who had to make some stroke adjustments to keep the ball on target. "It pocketed the ball well and launched it back with plenty of depth. I found myself taking power off my arm speed and increasing my wrist snap to maintain depth while adding more spin. For my flatter shots, I had to be very precise; otherwise, the ball would travel long. The strings notched badly after I hit with them for more than an hour, and the depth increased, resulting in decreased accuracy."

Spin - Score: 73

According to our playtest team, RPM Soft does not have the sharp bite or vicious snapback found in the game's best spin strings (aka polyester) such as RPM Blast. Nor is RPM Soft durable enough to withstand the violent sliding action caused by topspin mechanics. That said, Andrew found plenty of spin at the beginning of the playtest. He said, "The spin was prevalent for this category of string. For a string with co-poly wraps and a polyamide core, the spin was great when it was fresh off the stringing machine. After less than an hour of hitting, though, a loss of spin and control was noticeable, and the strings began to notch in all setups and tensions. When I attempted to use a stiffer poly main with RPM Soft in the crosses, RPM Soft's coating was too sticky and did not allow the main strings to snap back the way I hoped they would.Ó

For Chris, RPM Soft simply did not live up to his expectations in this category. He said, "Spin generation was just average with this string and not up to the high spin standards of most polys. I found the main strings to consistently get stuck out of position, so I wasn't getting any snap back to help give the ball a little extra kick of spin. I did get the sense the stringbed was biting the ball decently, but the launchy nature of the string made it tough to trust control on the high swing speeds one needs for maximum spin. With this string I had to hold back at times to prevent overhitting, whereas a good poly encourages higher swing speeds, which results in more spin."

Comfort - Score: 88 / Feel - Score: 80

With its low stiffness level, RPM Soft was one of the most comfortable strings our team has playtested. It also avoided the mushy feel that sometimes afflicts softer strings. Although Chris typically uses a much stiffer string, he appreciated this string's classic feel at net. He said, "RPM Soft was a very comfortable string. I thought it pocketed the ball very well. I tried RPM Soft in stiff, powerful racquets, and it played with much more comfort than the typical poly-based strings I use. I enjoyed the feel at net the most, where the softer response of the stringbed seemed to be more of an advantage."

For Andrew, RPM Soft was not only comfortable, but it also felt predictable, which is not always the case with softer strings. He said, "RPM Soft was very arm friendly, and I never had any discomfort in multiple tensions or setups. The ball pocketed well, and I could predict where it would land after contact."

Playability Duration - Score: 60

Although RPM Soft posted a great tension maintenance score in our Tennis Warehouse University string lab, our playtesters reported excessive notching and string displacement over time. For Andrew, these problems led to playability concerns. He explained, "There was no issue with string breakage, but notching was the biggest durability issue with RPM Soft. From the time the string came off the machine and arrived on the court, it began 'clicking' or notching. The strings were no longer snapping back into place less than an hour into hitting, and string movement required me to reset the strings after big hits. The resulting loss of spin and control was very noticeable. It held up best when using a multifilament cross at mid tensions."

"I found RPM Soft to notch very quickly in my racquets, so playability duration wasn't great," said Chris. "With that said, the string remained decently durable, especially so in the dense stringbed of my Tecnifibre TF40 305, and it held tension better than most polys."

Overall - Score: 72