Babolat's RPM Blast first burst onto the scene back in 2010 when Rafael Nadal showed up in Melbourne with a new black octagonal string that nobody had seen before.
Although it didn't result in an immediate title for the Spaniard, he won the next three Grand Slams with his devilish forehand spin which helped build the hype from there.
Since then countless pros and recreational plays have strung up their racquets with this co-polyester, and it's currently the string of choice for players like Dominic Thiem, Jo-Wilfried Tsonga and Fabio Fognini.
So how does it play? Is it an excellent choice for a club player or it exclusively suited to big hitters with heavier racquets seeking maximum spin? Let's take a look in this Babolat RPM Blast Review.
Babolat RPM Blast Specification
Packed with the latest technologies, this high-density co-polyester monofilament string offers a totally unique feel and a powerful, ultra-high-speed response. The octagonal section and cross-linked silicone coating allow the strings to quickly return to their original positions and “bite” the ball better for maximum spin. How Babolat Pitches RPM Blast
String Used For This Review
- Polyester monofilament, octagonal profile.
- Stiffness: 189 lbf/in or 3.38 kgf/mm. This is considered stiff.
Racquet Setup For Testing
- Strung at 23 kgf (roughly 51 lbf) as one piece
- Frame: Dunlop Force 98 Tour, 310 g unstrung, 333 g full kit.
This is the first time I get to try a string that is widely used on the ATP tour, including no less than Mr Nadal. Babolat RPM Blast comes rated as one of the most spin-friendly strings on the market.
It has been around for about a decade and has test reports abound, so this is just another personal view on a popular piece of equipment, and I hope my insights are of some usefulness.
The type-tested is the 18 Gauge (1.20 mm), which is the thinnest tennis string you'll commonly find, so it should theoretically be a little softer than the 16 G types of other similarly stiff polyesters I've tried.
A foreword about the setup: I strung this on a Dunlop Force 98 Tour, which is a medium-heavy frame: 310 g, 98 sq.in head, 31 cm balance unstrung and abnormally low swing weight (313 g.cm2 strung) for its class.
You'll find a few reviews about it on the net and not all very positive, but I'll save that for another day. It came strung with the usual and boring stock multifilament Dunlop Silk at around 23 kgf, which wasn't doing any favours to control, so I had it cut and restrung the frame with RPM Blast at 23 kgf.
How It Looks
The string itself is very slick. As is often the case with most shaped polyesters, especially with an even number of faces, mains and crosses slide and snap back against each other very easily.
The string edges are noticeable but not much: having eight of them implies that the angles are shallow, so a stringer should not have any complaints with the job.
The whole kit looks very mean indeed: a dark glossy frame with splashes of abstract cyan and grey shapes with shiny black strings is a menacing sight… if only the guy swinging it was up to the occasion!
How Babolat RPM Blast Plays
Whoa! RPM Blast is firm. A couple of groundstrokes tell you immediately that this is a heavy-duty string. The impact is so direct and substantial that it feels as if you are hitting the ball hit with a mallet, with minimal, if any, harsh post-impact vibrations that are found on stiffer polyesters.
It's as if all the feedback were concentrated where/when it should, with just the right dampening: not too muffled and not too harsh, and this is where I think the materials' engineers at Babolat stroke (pun intended) a very happy medium. But let me be clear on this: RPM Blast is not a comfortable string in absolute terms, but it's perfectly bearable provided it's strung on a sturdy frame to handle it.
In this regard, it's not that dissimilar to Tecnifibre Black Code, but while the latter yields a somewhat muted and disconnected impact, with off-centre shots feeling like hitting with a wooden plank, RPM Blast feels crisper and more tolerant. Some of this impression is possibly biased by the lower tension and string diameter, but the frame head is also smaller, so I think the comparison holds.
On slower strokes, I found a surprisingly soft side (relatively, that is) that provides just enough feedback to make touch shots much easier than expected. For a polyester string, this is quite a feat, especially considering the string firmness on heavier strokes.
This may sound like a dull statement, but the control provided by RPM Blast is great.
On flat strokes, which is not quite the type of play that polyester strings are designed for, RPM Blast seems to have just the right blend of crispness and elasticity to pocket the ball and convey the sense of where it's going to and, most importantly, how far it's going to travel.
I was particularly impressed by being able to defend back fastballs on the stretch that would otherwise die at the net. Sure enough, by that time the opponent was standing at the net just to kill the point, but I'd rather not elaborate too much on that…
Add a little spin (see below), and it almost feels like driving the ball with a remote control. Of course, all of it requires proper technique: weak strokes will see the ball speed dip steeply as more spin is added.
You need to keep a constant high level of energy in the strokes (you'll read the same statement that in any review of polyester strings).
Don't ever forget the laws of physics: the more spin is put on the ball, the more linear speed is drained from it. If you relax/get tired /are not fit, you'll have fun for a while, and then it's gone, unless you are playing against your 10-year old nephew.
As can be deduced from the above, the power return provided by RPM Blast is low and not too different from other polyester strings. I estimate it to be about average in the class but bear in mind that I haven't tried many.
For example, it feels less “powerful” than Dunlop Black Widow but a little more than Black Code, both the original and 4S. I usually gauge the power return from the frequency of flat forehands that sail out on me, and I have to say that I was quite happy with the statistics I got with RPM Blast.
On the other hand, I wouldn't refuse a little more power because the level of fitness this frame & string setup requires is just flirting with my limits. It's fine when I'm fresh, but after one hour the wear starts to show.
On services, flat ones posed very little difficulties, provided I swung the racquet smooth and loosely, just as I had no trouble whatsoever with its cousin stroke, the overhead. Neither had much power, just the adequate, but good placement comes first, so it's a great excuse to start doing some push-ups regularly.
However, on strokes with little or no swing to help, such as a volley, the task requires a bit more work. It's a straightforward affair to deflect the ball back with good direction but adding a little punch for a put-away volley required a strong arm and wrist because RPM Blast's low elasticity will not help you there. And neither will most polyesters, for that matter.
In a nutshell: it's a banquet at your disposal in case you have the flatware, read “I pay attention to my coach and practice all the strokes he teaches”.
Here, I cannot fully dissociate the string's properties from the frame construction because the spacing is very even, resulting in an open string pattern in the middle of the string bed.
Considering all this, it's not surprising that RPM Blast feels like it's grabbing the ball with claws, so much so that in my first practice session I did zero double faults (was it?) in a set, as my second service, mostly sliced, insisted on landing inside the service box time and again.
Sure enough, the power was having a holiday somewhere else, but the sense that the strings were doing what they were asked to was unique.
My backhand is mostly flat, so I cannot get many benefits on that side. However, if you like to slice, RPM Blast can vary quickly turn that stroke into a severe addiction.
The first time I tried it on a drop shot, my opponent found himself hopelessly chasing a ball that bounced 90 degrees away from him to his right. Needless to say, I had an enormous amount of fun on backhand service returns.
On the forehand side, since I have a semi-western forehand, I can feel the difference to a less spin-friendly string. I found a more significant safety margin on approach shots down the line – a shot I'm not particularly confident at – but the tastiest invitation was to go for short cross-court forehands, which usually account for about half my winners (and unforced errors too).
The capability of a string to keep its spin potential relies heavily on the snapback. RPM Blast is slick, stiff and has an even number of faces, so it's not a surprise that after about 8-10 hours of practice mixed with play, I noticed just a little notching and the occasional scraping sound on strokes with more spin.
A higher-level player might start to get annoyed earlier than that, but for me, the durability is perfectly fine. So far, tension seems to be holding well but, again, it takes a hard-hitting player to put this parameter to real testing.
How To Get The Most Out Of RPM Blast
Like any stiff polyester string, this one is not suited to light frames. Don't even think of putting it on a 270 g frame; you need mass to handle the ball impact so unless you want to play the drums in an industrial rock band, stay clear.
On 300g and above, start at 23 kgf maximum and work your way up or down according to your taste. I would honestly stay below 25 kgf unless I were Mr Universe waving a 330 g frame. Anyway, polyester strings perform their best at lower tensions.
Who I Think RPM Blast Is For
An intermediate player/student, physically fit and starting to hit harder and with some spin, seems to be the minimum to fully appreciate and get benefit from the versatility RPM has to offer for a polyester. Beginners should pass.
RPM Blast is a great polyester string, not because of some absolute measurement but because it achieves a complicated balance between mutually exclusive properties.
It's very firm without getting uncomfortable and dampened in just the right measure to kill harsh vibrations, but not so much that it takes away the feedback.
The power return is average for a polyester, perfectly complemented with copious amounts of spin at your disposal to tame harder strokes and try other fancy ball trajectories.
If you have the tools, RPM Blast will give you all the control you want.
So far, despite being a little too demanding for my level, this is the polyester string that has impressed me the most with its exquisite balance of attributes.
Keep in mind that this is nevertheless a stiff string directed to medium and high-level players. It's clearly made for hitting hard but with decent room for craftier shots.
- Firmness and very live/direct feedback
- Great control with a surprising feel on slower strokes
- Spin at will
I didn't like so much:
- Requires full stroke commitment, both physical and technical.
- The firmness can feel a bit unpleasant at first.
- No free power
Have you tried Babolat RPM Blast? Have any questions about it? Let me know in the comments.