ReString Strings Review: Sync vs Zero vs Vivo

ReString runs a short lineup on purpose. Three co-polys and a test box, instead of forty sets that overlap. That makes the brand easy to explain and easy to get wrong, because the three strings look similar on a shelf and behave differently on a stringbed.

Here is what separates them, using the specs on the packet and what we see when they go into customer frames.

The lineup at a glance

String	Shape	Gauges	Leads with	Start here if
Sync	Round co-poly	1.20 mm (18g) / 1.25 mm (17g)	Control, feel, tension retention	Your frame already has power, or you need a cross
Zero	Hexagonal monofilament	1.23 mm (17g) / 1.28 mm (16g)	Spin bite and snapback	You swing fast and hit heavy topspin
Vivo	Hexagonal, recycled polyester	Single gauge	Control and predictability	The ball is flying long and you want it to stop
Custom Box	5 Zero + 5 Sync	Mixed	Testing before you commit	You are still deciding

ReString Sync: the control set, and a great cross

Sync is a round co-poly with a slick profile, which is the combination that lets the mains slide and come back into place. Round means less mechanical bite than a shaped string and a cleaner, more predictable launch. You feel the ball longer and the trajectory stays where you put it.

ReString gives it in 1.20 mm and 1.25 mm and recommends 22 to 27 kg (48 to 60 lbs). The thinner 1.20 adds feel and spin at the cost of durability. The 1.25 lasts longer and reads slightly firmer.

The part most reviews miss: Sync is one of the best cross strings we use, in any brand. Round, slick, comfortable, and it holds tension better than most, which matters more in a cross than anywhere else. Put it under almost any shaped main and the snapback goes up. The full argument is in the best tennis strings for crosses.

Best for: all-court and control players, baseliners on powerful frames, and any hybrid that needs a cross.

ReString Zero: the spin set

Zero is the brand's flagship, a hexagonal monofilament built around bite and release rather than raw power. Six edges grip the ball on contact, then the main snaps back cleanly. That is where the spin comes from, and it is why Zero rewards a long, fast swing and punishes a short, tentative one.

It comes in 1.23 mm and 1.28 mm. Take the 1.23 for spin and feel, the 1.28 for durability and a firmer, more contained response. Tension retention holds up better than most co-polys in this bracket, so the stringbed stays lively for longer before it goes flat.

Zero is not the softest poly on the market. If your arm complains, string at the bottom of your usual range or put Sync on the cross.

Best for: topspin baseliners, fast full swings, open-pattern frames.

ReString Vivo: the control string of the three

Vivo shares the hexagonal shaped profile of Zero and is made from recycled polyester, packed in a paper sleeve. On the shape alone you would expect another spin string. On court it is not one.

Vivo is firmer and stiffer than Sync, and firmer than Zero as well. What it gives back is control and a more predictable response. It has less snapback than Zero, and less than a shaped Toroline set like O-Toro. It is a control string with a shaped profile, not a spin string.

That is a good thing when the problem you are solving is depth. If the ball keeps flying long and you want the trajectory to stop moving on you, Vivo is the answer in this range.

ReString recommends stringing it about 2 lbs lower than your usual poly. Take that seriously. Most of the disappointed first impressions we hear about firm polys come from someone who kept their old number.

Best for: players who need control and predictability, and anyone choosing gear on sustainability as well as performance.

The hybrid we build most: Vivo mains, Sync crosses

Vivo on its own is firm. Put Sync on the crosses and the whole setup changes character: more feel, more snapback, more comfort, and the control from the Vivo mains stays where it was.

It works because the two strings do opposite jobs properly. Vivo grips and holds the line. Sync is round and slick enough to let the mains move and recover, and it carries a large share of the impact so the bed stops feeling harsh.

If you like the idea of Vivo but found it stiff, this is the version to try before you give up on it.

Custom Box: stop guessing

Strings are personal in a way rackets are not. The same set can feel perfect in a 16x19 and dead in an 18x20. The Custom Box holds five sets of Zero and five of Sync in an FSC-certified box, which is the cheap way to answer the question with your own arm instead of a review.

Ten sets is roughly a season of restringing for a club player who plays twice a week. By the end of it you will know which side of the control-spin line you sit on, and then a reel makes sense.

Tension, and the mistake almost everyone makes

All three of these are co-polys, and co-poly plays stiffer than multifilament at the same number. Coming from a multi or a synthetic gut, drop 2 to 3 kg. Coming from another poly, start where you were and adjust from there.

Poly also dies before it breaks. It loses tension and starts launching long while it still looks perfectly fine in the frame. If your depth control goes and you have not changed anything else, the string is finished. Our string tension guide covers how to pick a starting number for your frame and pattern.

We string every set to your target tension before it ships, so tell us the number when you order. If you are not sure what it should be, send the racket, your current string and what you want to change.

ReString against the rest of what we carry

We were the first shop in Europe to sell ReString, in 2023, alongside Toroline. They solve different problems.

Toroline leans on a low-friction coating across most of the range, so the spin comes from how fast the mains recover. ReString Zero and Vivo go at it through shape, with six edges doing the gripping, and Vivo then pulls that back toward control. Sync sits closest to a classic round control poly and doubles as one of the best crosses either brand makes.

If you are choosing between the two, Sync and O-Toro are the two safest first sets. Everything after that depends on your swing.

For the wider comparison, read the strings that last longer than ALU Power and Toroline strings reviewed.

FAQ

Which ReString string is best?

There is no single best. Sync wins for control, feel and crosses. Zero wins for spin and snapback. Vivo wins for control and predictability. Sync is the safest first set for most players.

What is the difference between ReString Zero and Vivo?

They share the hexagonal shaped profile, and they play differently. Vivo is firmer and stiffer, with less snapback and more control and predictability. Zero is the spin string of the two.

Is ReString Sync a good cross string?

It is one of the best we use, in any brand. Round, slick, comfortable and strong on tension retention, which is exactly what a cross needs to let the mains snap back.

What tension should I use for ReString Sync?

ReString recommends 22 to 27 kg (48 to 60 lbs). Coming from a multifilament, start at the lower end and drop 2 to 3 kg from your old number.

Is ReString good for the arm?

These are co-polys, so none is a comfort string by design. Sync in 1.20 mm at a low tension is the gentlest, and a Vivo main with a Sync cross is the comfortable way to run the firmer string.

Where can I buy ReString strings in Europe?

From us, shipped from Portugal with no customs wait inside the EU. We were the first in Europe to carry the brand. See where to buy ReString strings in Europe.

Pick a set for your racket

Browse ReString at Tennis Rackets Europe, or send us your racket, your current string and tension, and the one thing you want to change. We will tell you which of the three to start with, and we will tell you if the answer is none of them.