Is ERT-300 or Mini-STT useful or a must for stringer?

Dr. Perry

New User
My daughter practices tennis daily (5-6 days a week) and I am concerned if she knows when to ask to have the racquet restrung (she is turning 11). Do you think a tool like ERT-300 or mini stt can address the concern? Or I should simply restring the racquet once every 12-15 hours?
 

esgee48

Legend
Depends. (Wishy Washy Answer, I know!) The 2 devices you mentioned measure string bed stiffness. Your daughter or you would have to know what is her range of optimal SBS for you to decide that it is time to restring. Mikeler's answer assume you know what range of tensions are optimal before you need to restring. It is a $1.99 option which works very well. Also from the same guy, you can get a range of tools. I prefer the Gamma String tension Tester just so I can determine when the reference tension drops too far. It isn't anywhere as accurate as RT, but you can still determine tension drops and you don't have to buy an iPhone.
 

Dr. Perry

New User
I heard of racquetTune a lot. You need to generate the vibrate yourself, don't you? Would it affect the result as your tap would be different from time to time? It seems it functions like mini stt.
 

Irvin

Talk Tennis Guru
I heard of racquetTune a lot. You need to generate the vibrate yourself, don't you? Would it affect the result as your tap would be different from time to time? It seems it functions like mini stt.
You're correct and you also have to position the racket so the vibrations are picked up properly with RacquetTune. Sten suggests using a hard object like a screwdriver or spoon and always tap the racket in the same location. Also you have to be in a location with very low background noise. It is best if you build a custom string for each string you use. All in all it is a good app if used properly but like any other tool if you don't use it right - garbage in garbage out.
 

mikeler

Moderator
I heard of racquetTune a lot. You need to generate the vibrate yourself, don't you? Would it affect the result as your tap would be different from time to time? It seems it functions like mini stt.
Most times, the readings are either the same or off by 0.1 or 0.2 pounds. Well within the type of accuracy you need to measure tension loss. Calculating custom string factors is a pain, so I only use it to measure tension loss and not absolute tension. It does a good job of this IMHO.
 

hyperion99

Semi-Pro
My daughter practices tennis daily (5-6 days a week) and I am concerned if she knows when to ask to have the racquet restrung (she is turning 11). Do you think a tool like ERT-300 or mini stt can address the concern? Or I should simply restring the racquet once every 12-15 hours?
I personally like the ERT-300 for its consistency.
It make its own vibrations to determine the tension of the racket(you need to use the wheel that comes with the ERT-300 to translate dynamic tension to actual tension).
http://www.tennis-warehouse.com/descpage-ERT300.html


Check out this video.
This talks about the ERT-300 and the racket tune app(I have never used racket tune).

http://www.youtube.com/watch?v=FcXvDWI3EwU

Dynamic Tension:
Stringbed stiffness (measured in DT - Dynamic Tension) is the major parameter that determines the playing characteristics of a tennis racquet. This value represents the force which is necessary to push down the stringbed for 1 cm in a contact area about the size of a tennis ball. The DT value is dependent on a number of parameters: string pattern, string, tension, stringer, time point of measurement and so on.

Hope this information helps.
 
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Dr. Perry

New User
Is the device well built? The claws are made of platstic, did it concern you?

I personally like the ERT-300 for its consistency.
It make its own vibrations to determine the tension of the racket(you need to use the wheel that comes with the ERT-300 to translate dynamic tension to actual tension).
http://www.tennis-warehouse.com/descpage-ERT300.html


Check out this video.
This talks about the ERT-300 and the racket tune app(I have never used racket tune).

http://www.youtube.com/watch?v=FcXvDWI3EwU

Dynamic Tension:
Stringbed stiffness (measured in DT - Dynamic Tension) is the major parameter that determines the playing characteristics of a tennis racquet. This value represents the force which is necessary to push down the stringbed for 1 cm in a contact area about the size of a tennis ball. The DT value is dependent on a number of parameters: string pattern, string, tension, stringer, time point of measurement and so on.

Hope this information helps.
 

Dr. Perry

New User
When I look at the number of views and replies, I can say neither item is a MUST. Maybe there is a more practical way to gauge a racquet's restring timing. My guess is ERT-300 is too pricy and Mini-STT's market awareness is low.
 

Irvin

Talk Tennis Guru
I have an old stringmeter I got probably 30 years ago. For some reason I called Stringmeter about something and they thought my Stringmeter was broke and offered to send me a replacement. I don't think there is a cheaper or easier to use tool out there that carries with it a guarantee like the Stringmeter. Yes RacquetTune is low cost but requires an iPhone or iPad and they aren't cheap.
 

Irvin

Talk Tennis Guru
I wonder if racket tune is gonna be available for the android any time soon.
Sten (the developer Stone Age) says there is not enough interest to justify it. I will try to find the quote.

EDIT: This quote is from three years ago but I don't think he has changed his tune any.

And I will give roughly the same reply :)
Android maybe, the others very unlikely. It is more fun (even if not commercially smart) to develop new apps and new functions in the existing ones than to support different software and hardware platforms. So nothing in the short term, but maybe eventually.

Sten
 
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Dr. Perry

New User
I looked into stringmeter too. Compared to ERT-300, Mini STT, racquet Tune ..., is this simple device good enough to tell about the stringbed?

By the way, I don't recall seeing any of these is found in the pro's bag check.

I have an old stringmeter I got probably 30 years ago. For some reason I called Stringmeter about something and they thought my Stringmeter was broke and offered to send me a replacement. I don't think there is a cheaper or easier to use tool out there that carries with it a guarantee like the Stringmeter. Yes RacquetTune is low cost but requires an iPhone or iPad and they aren't cheap.
 

hyperion99

Semi-Pro
I looked into stringmeter too. Compared to ERT-300, Mini STT, racquet Tune ..., is this simple device good enough to tell about the stringbed?

By the way, I don't recall seeing any of these is found in the pro's bag check.
Tour players restring their rackets every day so they don't really have a need to have these tools in their bag.
 

hyperion99

Semi-Pro
Sten (the developer Stone Age) says there is not enough interest to justify it. I will try to find the quote.

EDIT: This quote is from three years ago but I don't think he has changed his tune any.
Thanks Irvin.

Android has advanced a lot in the last few years though.
Maybe he can consider it since there's more of a market now than 3 years ago.
 

Irvin

Talk Tennis Guru
Actually I have seen Wozniacki use it quite frequently on the court...
Yes you beat me to it. But don't believe everything you hear and only half of what you see. Who knows if she is using it to see if it is time to switch or because she is paid to use it? Maybe she likes to use it to test the string bed when it does really feel good (or bad) to see what tension to use for restringing.
 

Rabbit

G.O.A.T.
Yes you beat me to it. But don't believe everything you hear and only half of what you see. Who knows if she is using it to see if it is time to switch or because she is paid to use it? Maybe she likes to use it to test the string bed when it does really feel good (or bad) to see what tension to use for restringing.
I don't believe the ERT gives a tension you can set on a machine, it gives Dynamic Tension which is vastly different.
 

hyperion99

Semi-Pro
Yes you beat me to it. But don't believe everything you hear and only half of what you see. Who knows if she is using it to see if it is time to switch or because she is paid to use it? Maybe she likes to use it to test the string bed when it does really feel good (or bad) to see what tension to use for restringing.
If the pros are switching their rackets every few games I don't see the reason for them to have the ERT at this point.

I think it could be more of a sponsorship deal than anything else (I could be wrong though).
 

Irvin

Talk Tennis Guru
If the pros are switching their rackets every few games I don't see the reason for them to have the ERT at this point.

I think it could be more of a sponsorship deal than anything else (I could be wrong though).
Not all pros switch their rackets every few games.
 

RJYU

Rookie
Actually I have seen Wozniacki use it quite frequently on the court.
She uses it to find out when she wants to change to a new racquet. She doesn't have a set game schedule when for she changes frames, so she's checking the DT reading. When it drops to a certain DT reading, she grabs a new stick.
 

Dr. Perry

New User
This is the only incident I can find a pro uses the ERT-300. Maybe its usefulness is limited?


She uses it to find out when she wants to change to a new racquet. She doesn't have a set game schedule when for she changes frames, so she's checking the DT reading. When it drops to a certain DT reading, she grabs a new stick.
 

hyperion99

Semi-Pro
Not all pros switch their rackets every few games.
Most pros switch there rackets after a few games (no set number of games because it's personal preference) unless they feel they are having a good streak and feel with the racket they are currently playing with.
 

Rabbit

G.O.A.T.
Most pros switch there rackets after a few games (no set number of games because it's personal preference) unless they feel they are having a good streak and feel with the racket they are currently playing with.
Well, this isn't necessarily true. There was an article by a guy from Luxilon who said that the vast majority of pros do not change their racquets after a few games. He said there was a minority at the top of the game who did this, but most pros did not.

RJYU, if you're still reading, do you have any thoughts? I also thought I saw where John Isner doesn't restring all too often or change frames on a time clock.
 

corners

Legend
If you have an iPhone then download RacquetTune.
In my opinion RacquetTune is far superior to an ERT. RacquetTune has been validated and is extremely accurate. It does not tell stringbed stiffness, but can tell you tension loss very accurately.

An ERT measures static stringbed stiffness. This is essentially useless because each string type has a different relationship between static stiffness (how stiff it is when pushed on slowly) and dynamic stiffness (how stiff it is during a fast impact, like when hitting a ball.) For example, gut and copoly stringjobs will test quite similar on an ERT, but we know from lab tests that in dynamic play gut is half as stiff as copoly. So an ERT can tell us nothing about how stiff a stringbed is during play.

I suppose an ERT can still be used to show a change of static stringbed stiffness over time, which could then be used as an indirect method of estimating tension loss. But with racquettune you can measure tension loss directly, not indirectly. ERTs are obsolete technological relics.
 
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jazar

Professional
This is the only incident I can find a pro uses the ERT-300. Maybe its usefulness is limited?
Plenty of pro players use ERTs, but they just don't do it on court. Some like to check on the ERT straight away when they pick the racket up from the stringer.
 

RJYU

Rookie
Well, this isn't necessarily true. There was an article by a guy from Luxilon who said that the vast majority of pros do not change their racquets after a few games. He said there was a minority at the top of the game who did this, but most pros did not.

RJYU, if you're still reading, do you have any thoughts? I also thought I saw where John Isner doesn't restring all too often or change frames on a time clock.
Most pros certainly do not switch frames after a few games, and most pros don't even switch frames every ball change. I don't know the exact numbers, but I do know the majority of players don't have a set schedule for switching frames.
 

Rabbit

G.O.A.T.
Most pros certainly do not switch frames after a few games, and most pros don't even switch frames every ball change. I don't know the exact numbers, but I do know the majority of players don't have a set schedule for switching frames.
Thanks! (ten characters)
 

Dr. Perry

New User
Have you seen people carry mini-STT too? It makes sense to have a ruler-like device around after the stringing job is done. Just don't see it often on court.

Plenty of pro players use ERTs, but they just don't do it on court. Some like to check on the ERT straight away when they pick the racket up from the stringer.
 

hyperion99

Semi-Pro
Well, this isn't necessarily true. There was an article by a guy from Luxilon who said that the vast majority of pros do not change their racquets after a few games. He said there was a minority at the top of the game who did this, but most pros did not.

RJYU, if you're still reading, do you have any thoughts? I also thought I saw where John Isner doesn't restring all too often or change frames on a time clock.
Thanks for the feeback Rabbit.
 

nek4d

New User
And a couple more similar apps too, although their reviews are not good as racket tune.
Maybe they get better later.
 

struggle

Legend
I rarely even use my ERT-300, but if i'm gonna fiddle with such.....i don't care for the racquet tune app, although
i know many who use it happily. I just don't care to mess with all of the setup, etc.

The ERT gives me better info and much easier, but yes at a cost.
 

Rabbit

G.O.A.T.
@struggle I bought and ERT and subsequently sold it. I just don't see the need. I also have RT and likewise, don't see the need. Some of the WTA pros have them just to check the number right off the stringing machine to ensure they are getting consistent results. But as far as using it to determine when to restring, none of them use it for that as they restring most every day. I'm just not that good. :)

BTW - since the ERT is impossible to find, you can get what you paid for it.
 

LOBALOT

Professional
It is an interesting question actually. As an adult I know when my strings are shot by feel but it is hard to expect an 11 year old tournament player to know when their strings are shot.

I know for my son at that age we made sure he had a setup that would snap before (or at around when) the strings were gone. As I recall at that age he was playing with ALU/NXT hybrid and he would snap the NXT pretty quickly (Not a great setup I know).

In your case it sounds like she is not snapping string so am curious as to what she is using for a setup and also her racquet rotation. If she has 3 or more it should be easy to track as I would have her play with one of them until she hits whatever hour mark you think is appropriate and grab it and restring it and swap in a fresh racquet.

Personally, I don't find the tension readings a useful measure of string playability or maybe my son is sensing something else to identify the time to restring. There are times I use RT and feel like his string is shot and he doesn't want to restring as he likes how it is performing. Other times I think the tension is still good and he tells me the string is shot.
 

Karma Tennis

Hall of Fame
Personally, I don't find the tension readings a useful measure of string playability or maybe my son is sensing something else to identify the time to restring. There are times I use RT and feel like his string is shot and he doesn't want to restring as he likes how it is performing. Other times I think the tension is still good and he tells me the string is shot.
Do you religiously record your DT values and track the changes?

I have used RT (both iOS and Android versions) always to keep track of what's going on.

Record DT straight off Stringing Machine. Let racquet rest for 24 hours and then record DT again. The record DT again after every hitting session. Once DT has dropped 15% from the DT value recorded after the initial 24 hour Rest period, racquet is restrung.

For example,
DT = 36 (straight off stringer)
DT = 34 (after 24 rest period)
Racquet is ready to be restrung when DT = 29
 

LOBALOT

Professional
Do you religiously record your DT values and track the changes?

I have used RT (both iOS and Android versions) always to keep track of what's going on.

Record DT straight off Stringing Machine. Let racquet rest for 24 hours and then record DT again. The record DT again after every hitting session. Once DT has dropped 15% from the DT value recorded after the initial 24 hour Rest period, racquet is restrung.

For example,
DT = 36 (straight off stringer)
DT = 34 (after 24 rest period)
Racquet is ready to be restrung when DT = 29
I do check tension right off the stringing machine with RT to make sure I am consistent from restring to restring. That I believe is a very good idea just to check my work and I do that for every racquet I restring.

As I mentioned previously, I used to take periodic interim tension readings but did not find consistency between what was playable and a readings. I just think there are too many other factors including playing conditions which come into play.

By the way, I also have seen the fall off in tension after 24 hours.
 

struggle

Legend
@struggle I bought and ERT and subsequently sold it. I just don't see the need. I also have RT and likewise, don't see the need. Some of the WTA pros have them just to check the number right off the stringing machine to ensure they are getting consistent results. But as far as using it to determine when to restring, none of them use it for that as they restring most every day. I'm just not that good. :)

BTW - since the ERT is impossible to find, you can get what you paid for it.
Are they really that hard to find?? Hmmmm
 

esm

Hall of Fame
Are they really that hard to find?? Hmmmm
yeah.. was looking recently and most places were either out of stock or sold out.
remember seeing on at the other forum, and the seller was asking too much (for me anyway)....
 

struggle

Legend
yeah.. was looking recently and most places were either out of stock or sold out.
remember seeing on at the other forum, and the seller was asking too much (for me anyway)....
What were they asking (for reference)? I may just be offering mine up for sale...
I know what I paid and due to availability (lack of), I'm sure I could get it back
as @Rabbit mentioned above.
 
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esm

Hall of Fame
What were they asking (for reference)? I may just be offering mine up for sale...
I know what I paid and due to availability (lack of), I'm sure I could get it back
as @Rabbit mentinoned.
oh yeah, i think so - i am sure someone will definitely pay..
i remembered it was 300-ish euros :laughing:
 

Rabbit

G.O.A.T.
@struggle @esm - I had mine for about 6 - 8 months. I kept it in the case and had already replaced the batteries. I listed it on the for sale forum here. It was snapped up same day. The buyer tried to negotiate, but given nobody could find them, I wasn't going to take a loss. $200 + shipping. We agreed to $225 and both parties walked away happy. Since then, I have not wanted one, but have checked every so often on a few sites. There are none to be found.

I'm still playing with the natural gut @uk_skippy sent me BTW :)
 
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loosegroove

Hall of Fame
So the Mini-STT is essentially the same thing as the ERT except you have to manually ping the strings and it spits out "tension" rather than DT?
 

struggle

Legend
@struggle @esm - I had mine for about 6 - 8 months. I kept it in the case and had already replaced the batteries. I listed it on the for sale forum here. It was snapped up same day. The buyer tried to negotiate, but given nobody could find them, I wasn't going to take a loss. $300 + shipping. We agreed to $325 and both parties walked away happy. Since then, I have not wanted one, but have checked every so often on a few sites. There are none to be found.

I'm still playing with the natural gut @uk_skippy sent me BTW :)
Bam. I could use $300. Nothing like a good, solid investment. I should have bought several!!!

@Rabbit, tried to message you, but i'm not seeing it went through....
 
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