Hi Harry. Nice and useful video as always. I have a few thoughts about ERT device. I am in the stringing business for 12 years now, and I have been using ERT for almost 10 years. Here are some things that I have noticed: 1. ERT will measure correct DT on every racquet (presuming that you take a few measurement - I usually measure 3 times). 2. ERT will not measure DT in some situations (there are some racquets with intensive vibration dampening technologies that simply soak up the vibration that ERT is producing on the strings, especially if using multifillament strings). I was unable to read DT on at least 10 racquets. 3. Readings on the "translator" should not be taken for granted. ERT will not measure the same DT (if the racquets are strung on the same tension) if the head size iz different, if the stringbed density is different, if the type of strings are different, etc. These could be some points to check in another video. Keep up the good work. Best regards from Bosnia and Herzegovina. Sasa J.
In the video you see Harry making several mistakes against the manual. Very important for consistent measurements : Clip the ERT 300 in the center of the string bed, always in exactly the same place. For example 16 x19 pattern : 1 crochet on string 9 cross of head and other 2 crochets on string 11 cross of head (skip 10 cross), the hook on string 9 cross between string 8 on the left and string 8 on the right mains. Hold the racquet at the throat, don't touch anything else !! Important: The ERT 300 Tennis computer must be clipped at the center of the string bed. If it is placed outside the center, e.g. towards the top or bottom, the measured value will change. Normally in such a case the stringing appears to be tighter. This corresponds to the reality. We however are interested in the impact zone. Variations can also occur as a result of incorrect or defective stringing. For exact comparative measurements (rechecks) the ERT 300 must always be applied to exactly the same point, count or mark the strings.
The resonant frequency of string under tension is a function of the mass density of the string, the tension, and the length of the string. The ERT 300 measures only the resonant frequency of the string bed, so to back out the tension, it has to assume values for the linear mass density (g/mm) and length of the mains and crosses at the center of the racquet. Density varies with string material and gauge, and obviously the length of mains and crosses will vary by the shape of the head and head size. This is all to say that the tension measured by the ERT will be an approximation. If you string a racquet with a well-calibrated stringing machine at 53 lbs. and the ERT measures the tension at 51 lbs., probably the true tension is closer to 53 lbs.
Clamps always move a few mm and number of knots can all affect the tension. Ert300 is going to be accurate, but neither is a well calibrated machine. Best to just use the ert300 as a guide for tension loss calculation over time
I have been fine-tuning my string tensions since last fall and finally have it down to 54 or 55 pounds. Experimenting via trial and error without cutting them out if you don't like them is an expensive way to go. The alternative is playing with strings that are too tight or too loose. A device like this would allow you to get to the best tension for your string setup more quickly and with fewer stringings. So cool device.
I´m an owner of the ERT 300 since I started stringing and I´ve heard of this tool, but to measure right, for me e.g. I always count to the 9th string, skip the 10th and get the 2nd hook at the 11th string. I got the old one which is yellow/black and paid about 180€, they were hard to get for a long time, sadly it looks the same just with different color and good looking case, I don´t know if they even did an update to the software. For me I prefer about DT 37 freshly strung, it will loose about 1 DT at least (if not 2 or more) after one day of not playing with it. PS: there was also an ERT 700 long time ago.
Hi, interesting video. I have more or less just started my tennis journey. +3 years ago. Now 68 years young. Trying to find out what tools I need to do the best of my way of play. Me as a tennis player, I enjoy more an fairly agressiv style. Like to explore mordern tennis strokes. Therefore I started to follow up my string tension, regularly, using app "Stringster". It follows the same drop pattern as mentioned here, but the relationship between the stringing machine meassure and the "Stringer" differs some 2-4 kgs. Requested tension 22.5 kgs. Multifilament, non hybrid. Do you have one of those white board comparative videos, whereas different string tension tools are compared??
Harry...have you left your shop? We all enjoyed hanging with you in the shop in the Tennis Spin videos. It was like the tennis version of the Cheers bar in our heads.
I fully agree with Eric4458, Harry is indeed not putting the ERT300 in the middle and even touching the strings when measuring, this is not OK. I own this ERT300 since 1.5 years now (new version) and if you do the measuring each time in the same way, on the same racket, with the same stringing tension, you will get very consistent readings with the ERT300. One of my best buys.
Like has been mentioned several times already, you are not centering it consistently. You will get different readings based on where in the stringbed you hook it. My ERT always reads the same DT as reference tension when I take it off the stringing machine and check it in the middle of the stringbed.
Is it possible to test mains vs cross? Theres a lot of discussion about whether you should string crosses higher or lower than mains and I would love to see measured tensions of those setups
As an engineer, I am a little surprised by the user interface. Can't they source a touch screen that shows tension? Hard to believe a newly developed product selling for this much money requires a user to use a wheel. Does this product also comes with a slide rule and vacuum tubes?
It’s reading dynamic tension, not tension. For example a harder string at a set tension may have the same dynamic tension as a soft string at a higher tension. DT reads the stringbed resiliency to deflection.
While I don't necessarily expect the clip on unit to do all the calculations and display the tension, the 'slide rule' decoder device is almost laughable today. An app can do that easily and it won't get lost or damaged. Hard to figure why they haven't created a simple app...
So is it better to string a few lbs higher because it reduces within a few hours, or keep your tension the same because you are used to playing with reduced tension? Will it mess players up if they think their tension is one thing but it's actually lower, so they raise it..
Between competent stringers, who all use similar techniques (eg use knot tension etc) on decent commercial constant pull stringing machines I suspect the tension loss will be about the same, so a 52lb stringbed will always feel the same and it really doesn't matter that you start playing at 50lb. I think you'd need to be a pro to really worry about having a racket strung to constant DT.
@@jerome_morrowHas he left the shop though? I felt like I was part of that shop watching Tennis Spin, like a tennis shop version of the Cheers bar. We need to know!
I don't understand why they can't program the lookup table into the device. It's such a simple thing to do in hardware. I have a stringmeter that I bought for 25 bucks and it's pretty accurate. I wouldn't waste money on this digital device.
The only problem is that you are not holding in the same position on all the racquets, hold by the throat only, you were holding at least one by the head on one side also.
Or at least a phone companion app. What if the wheel gets lost or damaged? Can replacements be purchased? The ERT 300 was out of production for more than 10 years before being recently resurrected. ERT did sell a larger version of this that did not require a wheel and the screen displayed the DT. Unfortunately, it was not portable being mains powered and compromising the display and microprocessor unit with the sensor part on an attached cable.
there's a simple flaw in all of this: it assumes that the original tension measurement (at restringing) is accurate. What we really need is something that, independent of anything else, will actually tell what string tension the strings are at. For me, this doesn't do it. Definitely not at that price.
Hi Harry. Nice and useful video as always. I have a few thoughts about ERT device. I am in the stringing business for 12 years now, and I have been using ERT for almost 10 years. Here are some things that I have noticed: 1. ERT will measure correct DT on every racquet (presuming that you take a few measurement - I usually measure 3 times). 2. ERT will not measure DT in some situations (there are some racquets with intensive vibration dampening technologies that simply soak up the vibration that ERT is producing on the strings, especially if using multifillament strings). I was unable to read DT on at least 10 racquets. 3. Readings on the "translator" should not be taken for granted. ERT will not measure the same DT (if the racquets are strung on the same tension) if the head size iz different, if the stringbed density is different, if the type of strings are different, etc. These could be some points to check in another video. Keep up the good work. Best regards from Bosnia and Herzegovina. Sasa J.
In the video you see Harry making several mistakes against the manual.
Very important for consistent measurements :
Clip the ERT 300 in the center of the string bed, always in exactly the same place.
For example 16 x19 pattern : 1 crochet on string 9 cross of head and other 2 crochets on string 11 cross of head (skip 10 cross), the hook on string 9 cross between string 8 on the left and string 8 on the right mains.
Hold the racquet at the throat, don't touch anything else !!
Important: The ERT 300 Tennis computer must be clipped at the center of the string
bed. If it is placed outside the center, e.g. towards the top or bottom, the measured
value will change. Normally in such a case the stringing appears to be tighter. This
corresponds to the reality. We however are interested in the impact zone. Variations
can also occur as a result of incorrect or defective stringing. For exact comparative
measurements (rechecks) the ERT 300 must always be applied to exactly the same
point, count or mark the strings.
The resonant frequency of string under tension is a function of the mass density of the string, the tension, and the length of the string. The ERT 300 measures only the resonant frequency of the string bed, so to back out the tension, it has to assume values for the linear mass density (g/mm) and length of the mains and crosses at the center of the racquet. Density varies with string material and gauge, and obviously the length of mains and crosses will vary by the shape of the head and head size. This is all to say that the tension measured by the ERT will be an approximation. If you string a racquet with a well-calibrated stringing machine at 53 lbs. and the ERT measures the tension at 51 lbs., probably the true tension is closer to 53 lbs.
Clamps always move a few mm and number of knots can all affect the tension. Ert300 is going to be accurate, but neither is a well calibrated machine. Best to just use the ert300 as a guide for tension loss calculation over time
I have been fine-tuning my string tensions since last fall and finally have it down to 54 or 55 pounds. Experimenting via trial and error without cutting them out if you don't like them is an expensive way to go. The alternative is playing with strings that are too tight or too loose. A device like this would allow you to get to the best tension for your string setup more quickly and with fewer stringings. So cool device.
Great video. Love your stuff.
I´m an owner of the ERT 300 since I started stringing and I´ve heard of this tool, but to measure right, for me e.g. I always count to the 9th string, skip the 10th and get the 2nd hook at the 11th string.
I got the old one which is yellow/black and paid about 180€, they were hard to get for a long time, sadly it looks the same just with different color and good looking case, I don´t know if they even did an update to the software.
For me I prefer about DT 37 freshly strung, it will loose about 1 DT at least (if not 2 or more) after one day of not playing with it.
PS: there was also an ERT 700 long time ago.
Old or new version.....they are just the same 👍
Hi, interesting video.
I have more or less just started my tennis journey. +3 years ago. Now 68 years young.
Trying to find out what tools I need to do the best of my way of play.
Me as a tennis player, I enjoy more an fairly agressiv style.
Like to explore mordern tennis strokes. Therefore I started to follow up my string tension, regularly, using app "Stringster".
It follows the same drop pattern as mentioned here, but the relationship between the stringing machine meassure and the "Stringer" differs some 2-4 kgs. Requested tension 22.5 kgs. Multifilament, non hybrid.
Do you have one of those white board comparative videos, whereas different string tension tools are compared??
How does ERT300 compare to Tourna string meter or Gamma tension tester? Does result come close?
Harry...have you left your shop? We all enjoyed hanging with you in the shop in the Tennis Spin videos. It was like the tennis version of the Cheers bar in our heads.
Might want to check out Amazon reviews of the ERT 300.
I fully agree with Eric4458, Harry is indeed not putting the ERT300 in the middle and even touching the strings when measuring, this is not OK. I own this ERT300 since 1.5 years now (new version) and if you do the measuring each time in the same way, on the same racket, with the same stringing tension, you will get very consistent readings with the ERT300. One of my best buys.
Any thoughts on the Racquet tune app?
Like has been mentioned several times already, you are not centering it consistently. You will get different readings based on where in the stringbed you hook it. My ERT always reads the same DT as reference tension when I take it off the stringing machine and check it in the middle of the stringbed.
Would have been interesting to see how the tension cahnges after 1 hour, 2 hours, 24 hours and after playing for an hour at a give temperature
Is it possible to test mains vs cross? Theres a lot of discussion about whether you should string crosses higher or lower than mains and I would love to see measured tensions of those setups
The only thing you could do is try out different tensions in the main/cross then test the overall DT result at the end.
As an engineer, I am a little surprised by the user interface. Can't they source a touch screen that shows tension? Hard to believe a newly developed product selling for this much money requires a user to use a wheel. Does this product also comes with a slide rule and vacuum tubes?
It’s reading dynamic tension, not tension. For example a harder string at a set tension may have the same dynamic tension as a soft string at a higher tension. DT reads the stringbed resiliency to deflection.
While I don't necessarily expect the clip on unit to do all the calculations and display the tension, the 'slide rule' decoder device is almost laughable today. An app can do that easily and it won't get lost or damaged. Hard to figure why they haven't created a simple app...
I tried the discount code but doesn’t work?
So is it better to string a few lbs higher because it reduces within a few hours, or keep your tension the same because you are used to playing with reduced tension? Will it mess players up if they think their tension is one thing but it's actually lower, so they raise it..
Between competent stringers, who all use similar techniques (eg use knot tension etc) on decent commercial constant pull stringing machines I suspect the tension loss will be about the same, so a 52lb stringbed will always feel the same and it really doesn't matter that you start playing at 50lb. I think you'd need to be a pro to really worry about having a racket strung to constant DT.
Do you still have your shop Harry? Never see videos made in your store anymore.
It’s not his shop.
@@jerome_morrowHas he left the shop though? I felt like I was part of that shop watching Tennis Spin, like a tennis shop version of the Cheers bar. We need to know!
@@cam1210 Fair question, Harry has been with BGTN since 2009. Big change if he’s left.
I don't understand why they can't program the lookup table into the device. It's such a simple thing to do in hardware. I have a stringmeter that I bought for 25 bucks and it's pretty accurate. I wouldn't waste money on this digital device.
The only problem is that you are not holding in the same position on all the racquets, hold by the throat only, you were holding at least one by the head on one side also.
You think for the cost of this device they would of found a way to tell the tension without a cardboard wheel
Or at least a phone companion app. What if the wheel gets lost or damaged? Can replacements be purchased? The ERT 300 was out of production for more than 10 years before being recently resurrected.
ERT did sell a larger version of this that did not require a wheel and the screen displayed the DT. Unfortunately, it was not portable being mains powered and compromising the display and microprocessor unit with the sensor part on an attached cable.
11
Another gadget for the nerds to drool over.
there's a simple flaw in all of this: it assumes that the original tension measurement (at restringing) is accurate. What we really need is something that, independent of anything else, will actually tell what string tension the strings are at. For me, this doesn't do it. Definitely not at that price.
Doesn't look centered
300 is too much for this, wait till its ripped off and 50.
I was really hoping these would be $5 so I could afford one, so I looked it up...nope