Multifilament of the month – Isospeed Professional


The basic facts

  • Construction: Polyolefin Ribbons

  • Gauges: 17 (1.25mm)

  • Color(s): Natural

  • Available in: Sets

  • Feel: Extremely Comfortable. Low vibration.

  • Recommended to: all ability levels, but especially those whose chief concern is comfort. A great option for players with tennis elbow. Also perfect for adding feel and vibration dampening to a hybrid.


How does it play?

Isospeed Professional Classic does not have the name recognition of Wilson NXT, Tecnifibre NRG2 or Gamma Professional. Nor does it have the higher price tag. What it does share with these iconic multifilaments is comfort – outstanding comfort. In fact, in the TW String Lab this string received a stiffness score that places it closer to natural gut than any of its more famous peers. The unique ribbons that make up Professional Classic are pre-stretched under high heat. As a result, this string maintains playability quite well while also offering a more muted and controlled response than comparable strings. Finally, no mention of Professional Classic is complete without noting its “Best of Class” vibration dampening. Aside from natural gut, there are few other strings that are as effective at adding comfort to a stiff frame. Anyone in the market for an arm-friendly multi or the perfect hybrid cross is encouraged to give this one a try. (And the price is awfully hard to beat)

What our playtester said;

“Soft without being mushy.”

“Installed at the top of the tension range, this string enabled me to swing big enough to generate good spin. Control was excellent and I didn’t give away an inch of comfort.”

“High marks for tension maintenance, and surprisingly good durability.”

“Touch around the net is spectacular. And it has a level of precision and predictability that is typically seen with much firmer strings.”


Strings for big hitters on a budget…


Don’t get me wrong, I appreciate the magic of Babolat RPM Blast …

….with its innovative cross-linked silicone coating, vicious snap back and otherworldly spin. I also appreciate the miracle that is Luxilon, especially on the professional tour, where strings like Alu Power have enabled the tornadic angular whip of the modern topspin game, allowing for exponentially higher levels of spin and control. Indeed, it only takes a few topspin forehands with either of these strings to realize why consumers shell out top dollar.

Does this mean you have to spend over $10 to get a good string?

If a polyester string costs less than $10 will it not snapback? Will it prevent me from reaching my personal best tennis? I humbly submit that the answer is “no”. Savvy consumers who are willing to poke around can find great performance for a low price.

For the love of Gosen

Of course, if you don’t feel like poking around, just go to the Gosen string page. There you will find the sorts of low cost/high performance strings that make home stringers giddy. More specifically, you will find the original Polylon, which prompted our resident polyester expert, Chris Edwards, to declare, “This string is legit. Sweet as a nut right off the stringer.” Needless to say, after a few sessions with Polylon, it’s easy to conclude that the $2.95 price tag is a typo.

For a softer feeling poly at a great price, there is the technology advanced Polybreak which provides the incredible spin and control of the original Polylon but with a slightly more flexible response. Finally, no mention of Gosen is complete without paying homage to OG Micro, an extremely responsive synthetic gut which has long been the standard-issue reel for stringers in need of reliable hybrid parts.

Gosen Polylon

Gosen Polybreak

And Tourna . . .

Poly players who have not experienced any of Tourna’s co-polys are hereby advised to make some room on their demo list for Big Hitter Silver and Big Hitter Blue (which both come in Rough versions for added grip). These innovative co-polys are not only loaded with control, spin and feel, they are steals at under $8. For players who like comfy (yet crisp) polys, Tourna Big Hitter Black 7 offers a combination of bite, comfort and control that is near impossible to beat for under $10. As someone who ran lab tests on the early prototypes of this string, I can safely say that the Tourna crew is extremely serious about meeting their design goals. They also have an ultra-comfortable multifilament called Quasi-Gut which is softer than NXT and NRG2 (at half the cost).

Tourna Big Hitter Silver

Tourna Big Hitter Blue Rough

MSV and Topspin

Big hitters on a budget do not have to sacrifice liveliness or comfort as long as Topspin keeps making Cyber Blue and Cyber Flash. The results from our TWU lab tests place these amongst the softest polys on the market. Another company with some impressively playable low cost polys is MSV. You can start by reading our string review of Focus Hex, a medium-firm co-poly with incredible control. After that, give both Co-Focus and Hepta-Twist a serious look. These meticulously engineered co-polys fit perfectly inside the growing ranks of elastic, user-friendly monofilaments, offering advanced players a friendlier response without sacrificing any spin or control.

Topspin Cyber Blue

MSV Co.-Focus

MSV Hepta-Twist



Do something nice for your tendons – a short list of soft(er) strings

Natural Gut. known for its almost other-worldly feel and responsiveness, the obvious solution for players in search of ultimate comfort is natural gut. At once velvety and crisp, the fibrous collagen in beef serosa produces a sensation that must be experienced to be appreciated. For those with sticker shock, please note: unlike multis that go mushy or polys that get brassy, the tension maintenance of natural gut is second to none. If you’re looking to give it a try, check out Pacific’s line of natural gut, which has 4 of the 10 softest guts tested in the TWU string lab. Here are a couple to consider:

Pacific Prime Natural Gut 16

Pacific Classic Natural Gut 16

Multifilament: If you don’t have a cow handy, the most common method for creating a softer string is to switch out your solid core for an army of shock absorbing filaments (and it wouldn’t hurt to inject it with stretchy polyurethane). Simple right? Nope, because not all multifilaments are created equal. The number and type of fibers along with the amount and kind of bonding resin have a significant impact on playability and feel. On top of that you have to consider the coating, which is another area where composition has consequence. Abrasion resistant coatings will often trade a little comfort for durability. Needless to say, if one multifilament doesn’t feel quite right, keep looking because the perfect feel is just around the corner. In addition to the classics, e.g., Wilson NXT, Tecnifibre NRG2 and Gamma Professional, here are a few others to consider:

Dunlop DNA 16

Klip Venom 17

Tourna Quasi-Gut 16

Zyex: Let’s not ignore the hard data. Stiffness tests for Zyex based strings place them among the softest non-gut strings tested in the TW string lab. You don’t have to take my word for it, test drive Ashaway’s Dynamite 17 Natural or Dynamite 18 Soft. For a slightly firmer feel, try Dynamite 16 Tough. These strings seem to maintain control well at lower tensions, so don’t be afraid to shave off a few pounds. New to the Zyex universe is the paradigm shifting MonoGut ZX, the softest monofilament on the market. TW playtesters have commented that it offers the slippery snap back of a poly with less impact shock than a traditional monofilament.

Ashaway Dynamite 17 Natural

Ashaway Dynamite 18 Soft

Ashaway MonoGut ZX 16

Polyolefin: If you want to dampen the shock of your stiff frame, or maybe just spoil your elbow, look no further than polyolefin ribbon technology. Though built from a firm material, polyolefin ribbons produce a very comfortable response. In fact, TW lab tests confirm that along with Zyex, polyolefin-based strings are among the softest non-gut strings available. You can discover the vibration-free muted magic of polyolefins in a small number of strings, including IsoSpeed Control and IsoSpeed Professional, as well as a couple ultra comfortable Head hybrids, Intellistring and Intellitour. These hybrids feature the RIP Feel cross, which has one of the lowest stiffness scores of any non-gut string ever tested. Finally, there is the slightly stiffer Head RIP Control which features polyolefin ribbons wrapped around a multifilament core for a very unique, comfortably firm response.

IsoSpeed Professional 17

Head Intellistring

Head RIP Control 16

Co-poly: Yes, I know, polyester is stiff and has no business anywhere near a list of soft strings. In fact, when this rigid plastic stuff started popping up in the 80s it was not very well received, offering little more than durability to string breakers. But times have changed. The tipping point was in 1997 when Gustavo Kuerten won the French Open with something called Luxilon, which represented a crucial leap forward in monofilament technology. Since then poly-based strings have not only taken over the pro tour, but an increasing number of string manufacturers are devoting the lion’s share of their R&D to creating friendlier, more playable polys for those of us without Nadalian head speed or 13 ounce racquets. While the strategies and additives used to improve the playability and comfort of polyester strings are too numerous to mention, one thing is for certain: it’s working. An ever-expanding number of players are joining the party, all of them looking for more control on bigger swings. The list of softer polys gets longer every season. In addition to the recently reviewed Dunlop Black Widow, here are a few that we’ve been enjoying lately.

Polyfibre TCS 16

Topspin Cyber Flash 16

Weiss CANNON Silverstring 16L

Polyester based strings are quite firm compared to other string materials and are only included as an option for poly players who might want to explore softer options. Given the native firmness and low elasticity, reducing the tension from your nylon or nat.gut reference is a good call. 

Thanks for reading,


Product Review: Strings

As the resident product-video-girl I am regularly in front of the camera, focusing on different products that we have (specifically strings and bags!). Recently I did a whole bunch of string videos for your informational pleasure, so you can understand best what you’re playing with and putting in your racquet.

I’m working my way through covering all the strings that we have here at the Warehouse, in no particular order, so if you have any strings you want to see or have any questions, make sure you always contact us and ask!

Wilson’s Champions Choice String (we playtested this and did a review on it, which you can check out here).

Pacific Prime Natural Gut string (made in my homeland of New Zealand!)

Luxilon Big Banger TiMO string

Gosen Sidewinder string

Dunlop Silk string

Make sure to comment if you have any questions, I, or anyone else on the team will be happy to help.


Tennis Strings. Where to Begin?

If you’ve ever had the arduous task of going to the grocery store, then you understand that in 2011, there are way too many choices for everything you want. Need some bread? Would you like white, wheat, whole grain, 9 grain, potato, or buttermilk?  Take a stroll down the juice isle and you’re be bombarded with cartons that read: No Pulp, Less Pulp, Calcium Added, and Extra Pulp.

And don’t even get me started on the types of ice creams and flavors that are available. What in the world is a Dippin Dot?!

So I can relate to those of you who take one look at our string page and think, as the kids say, “WTF.” I’m fortunate enough to be in a position where I get to try out so many types and brands of strings that I know what to look for and I’m not intimidated by the vastness of the selection. Let me help you by breaking it down as simply and easily as possible.

Before we even get into string types, we should talk about tension. Every racquet has a recommended tension range and it usually lies between 50 and 60 pounds. As a general rule of thumb, the lower the tension, the more power and the higher the tension, the more control. Not sure what tension to go with? I recommend stringing at mid, and then making adjustments from there. Feeling like you’re slightly over hitting? Dial up the tension a couple pounds. Vice versa if you feel your shots are landing shorter than usual.

Now onto the string types. There are 4 basic string categories: nylon, multifilament, natural gut and polyester.

Nylon (AKA synthetic gut or syn gut):
Price Range: Less than $5.00
Pros: Cheap, does everything decently well.
Cons: Does nothing spectacularly well.
Examples: Babolat Synthetic Gut, Prince Duraflex, Gamma Synthetic Gut, Wilson Extreme
The most basic string type is also the cheapest. A jack of all trades, it provides decent spin, power, control and durability. This is ideal for the casual player and those looking for all around performance in an economical offering.

Prince Range: $5.00-$20.00
Pros: Soft feeling, arm-friendly, wide selection, powerful
Cons: Durability
Examples: Wilson NXT, Gamma TNT2, Babolat XCel Premium, Tecnifibre NRG2
Generally speaking, these types of strings are softer and better for the arm (those suffering from any arm injuries take note: These strings are for you!). They are made up of thousands of little fibers all wound together and provide great elasticity for power and ball pocketing. This is a great cheaper alternate to natural gut and offers all weather performance.

Natural Gut:
Prince Range: $20.00-$43.00
Pros: Comfort, arm-friendly, ultimate feel and insane ball pocketing.
Cons: Durability, price, doesn’t like damp or wet conditions.
Examples: Babolat VS, Wilson Natural Gut, Pacific Natural Gut, Klip Legend
Whether you’re recovering from an arm injury or trying to prevent one, this is the best possible string you can get for your arm. Provides a very soft and forgiving stringbed with plenty of power. Natural gut used to be used by just about every pro player until the invention of polyester strings (see next section). Natural gut is seeing a resurgence on the pro tour as part of a hybrid set up (different types of string used in the stringbed — one in the mains, the other in the crosses) as it adds comfort, pocketing and power to whatever string you combine it with. Natural gut alone has to be strung very tightly for big hitters to still have control, but because of its unique natural fiber construction it plays softer at higher tensions. Made from a cow’s intestine, this is not the string for members of PETA.

Price Range: $4.00-$20.00
Pros: Large selection, control, durability, spin
Cons: Stiff, lack of power, tension maintenance
Examples: Luxilon ALU Power, Babolat RPM Blast, Polyfibre TCS, Solinco Revolution, Becker Bomber, Signum Pro Poly Plasma
The hottest thing to hit the tennis world since graphite racquets or Anna Kournikova, take your pick. Most of the pro tour has already made the switch. The question is, is it right for you? What’s all the hype about? And it really boils down to two words: spin and control. Because it is so low powered, players are able to take full, big cuts at the ball, imparting more spin than ever before. The big downside is how harsh it can be on your arm. This is not an issue for the pros as they find the sweetspot more than the rest of us, but off-center hits can be very jarring. The high stiffness level does very little to help absorb all the shock and vibration. Avoid this one if you have arm, wrist or shoulder issues.

That is a very quick break down of the 4 main categories of strings. If you really want to dive deeper into the world of strings, I suggest you head over to our TW University. I hope this clears some things up for you and you are now able to narrow down the types of strings you want to try in the future.

And if not, there’s always Dippin Dots.

Jason, TW

I’ll Always Remember My First Time…

…with polyester, that is.

Before I became a playtester for Tennis Warehouse 4 years ago, I played exclusively with an inexpensive synthetic gut. I usually went with something like Prince Synthetic Gut or Gamma Synthetic Gut, though it really didn’t matter. I’d spend about $20 to have my racquet strung, then be back in a couple of weeks with a busted string for another string job. To me, that made the most sense as it was pretty much the least expensive (without resorting to nylon). Natural gut, I’d heard it was great, but that was not an option with the pricing. I mean, come on, why would I pay more than double for string that won’t last any longer? Synthetic gut is a fraction of the price and I’m sure can’t be too far off from natural gut. Heck, they’re both “gut,” right? I’ll stick with the less expensive one, thank you. At this point, my naivete in the tennis industry had limited my product knowledge, and I’d never even heard of polyester string. Polyester leisure suit? Sure. I was kickin’ around in the ’70s, so I’m familiar with that. But tennis string? I don’t think so.

Soon thereafter, I started working for Tennis Warehouse and eventually became a playtester as well as working in the Web Editing Department. I didn’t have much of a choice but to play with different product. Strings included. I was quickly brought up to speed on the vast selection of not only manufacturers, but different types of string within manufacturers. On top of that, all the different gauges. If you’ve had a difficult time trying to choose a racquet that works best for your game, finding the perfect string may even be tougher.

Being sent some sample packs of string from a manufacturer we had yet to carry as a brand, I strung up a couple of racquets with their strings. This was the first time I hit with a polyester, and I immediately noticed something different. The first thing I noticed was the ball pocketing — how the strings seemed to cradle the ball, then spit it out with more spin than I’d been used to. To say I loved this string was an understatement. It changed my whole outlook on string, let alone my tennis game. My control, both depth and direction, seemed to be more locked in. After hitting for a good session and taking good size swipes at the ball with no ill effects of balls flying out, the last thing I noticed was that I NEVER had to straighten the strings! What the heck was this?

It was Polyfibre Hightec, a soft co-poly.

Since then, I haven’t looked back. My preference in string is overwhelmingly polyester. (The leisure suits aren’t bad either!)  I’m lucky that I’ve been able to sample several different brands, gauges and compositions, giving me a great feel for what I like (and what my arm likes, too).

I continue to like Polyfibre string. Not because it was my first, but because they simply offer good playing string.

Spencer, TW.

Volkl V-Fuse 16 String Review


I love the control and spin I get from co-polyester strings. I also love the comfort and feel I get from natural gut. The new V-Fuse hybrid from Volkl aims to bring both to the court in one stringbed by combining Volkl’s Cyclone monofilament and V-Icon natural gut.

I tried this hybrid both ways by switching my choice of main and cross strings. The most conventional hybrid is to put the more durable, in this case the Cyclone, in the mains.

Call me a traditional guy because my preferred setup was to have Cyclone in the mains and V-Icon natural in the crosses. When stringing my racquet, I took a little extra care weaving the natural gut cross string. Stringing the gut in the crosses added a few minutes to my stringing time, but I’m not the world’s fastest stringer so I always try to schedule enough time to not rush. In other words, the few extra minutes stringing were no biggie.

Out on the court, I liked the control and spin I was getting with V-Fuse with the Cyclone in the main strings. If you’ve read some of my other blogs you’ll know about my penchant for low string tensions, and I went as low as 40lbs with this set up. I started at 52lbs in my Volkl Powerbridge 10 Mid, and the string felt very crisp and control oriented. I immediately thought I could get more pop out of the string by lowering the tension. I tried the string again at 48lbs with better results. Curious to see what I could really get from it, I and dropped more dramatically to 40lbs on my next stringing. At 40lbs this hybrid felt very soft and comfortable, and I found the extra power I was seeking and never had to give up any control or feel. It has become one of my favorite strings as the comfort is improved over an all poly setup, yet I still get very good spin and control — especially at low tensions.

By just simply switching the way the strings are oriented made a huge difference with V-Fuse. Putting the gut in the mains made the hybrid feel much livelier. I was also impressed by the control and feel the hybrid offered with the gut in the mains. At low tensions, this setup was not working at all for me. I was losing control at 40lbs and had to put effort into controlling the ball and prevent shots from sailing long. In sharp contrast to having the poly in the mains, 57lbs proved to be my preferred tension with the gut in the mains. I started out at 52lbs and moved my way up (with the exception of trying the string at 40lbs for a couple of weeks). The one downside for me by having the gut in the mains was durability. I just never found close to the durability I found with the Cyclone in the mains.

All in all, I really enjoyed playtesting V-Fuse. When strung with the Cyclone in the mains, V-Fuse has become one of my favorite strings. My best advice would be if you are trying this one after using a full stringbed of poly, don’t up the tension much if at all. With the Cyclone in the mains this hybrid played firmer and crisper than expected.



Becker Hero string review


It had been a while since I’d regularly used natural gut, but I recently started to play around with some hybrids and full sets of gut after a nagging wrist injury just refused to go away.

So, when some sets of Becker Hero natural gut came into the office for testing, I quickly grabbed a set to try out.

Because of a busy schedule, I did not get to install the string. Instead, I had one of our MRTs and fellow playtester, Sean, install the string. He reported no issues with an easy install.

On the court, like most natural guts, Hero offers exceptional ball pocketing. I could really feel the ball sink into the stringbed from the first hit. I was very pleased with the grip I was getting on the ball. That grip translated into some decent spin and a confidence-inspiring level of control.

What impressed me most about this string was the level of power I was finding on my shots. Hero feels pretty crisp, and I was finding a clean yet crisp feel with lots of pace off the stringbed. Everything from serves to big groundies was zinging away with excellent pace and depth. I felt connected enough to stay on the gas without a huge fear of over-hitting, and while I never felt as safe swinging away as I would with a low-powered poly, I was able to play aggressively.

One thing that really stood out was that in the racquet, the Hero looked thinner than its listed 16L gauge. It looked more like a 17L to me, which may explain some of its bite and power.

I quickly noted the one downside was going to be durability. I saw a fair bit of fraying on my first hit and had to stop midway through that hit and trim an errant strand from fraying any further. While I don’t hit with as much pace and spin as I did back in college, I still take a decent cut at the ball, and this seemed to have me taxing the durability of the string.

Hero settled in nicely, and I really liked the playability. The comfort was outstanding, but durability would be a concern for me — especially considering the price of natural gut. All in all, I came away impressed by the crispness, power and comfort. For me, this might make a great hybrid option as a cross string to go with something like Volkl Cyclone.