Accurate tension / Am I doing something wrong.

[AA5B Tiger]

I have a Gamma 602 Fixed Clamp Dropweight machine.

Have strung many of my racquets yet felt the tension was too high; the racquets were just board-like. Then one day I was talking to a friend/pro/stringer who plays with a Wilson 6.1 95 and had some poly at 55 in that frame. I mention that I couldn't handle a tension that high -- and he asks to feel my racquet (Head Radical) that was supposedly at 48. From every subjective test -- squeezing the strings together to sound test of pinging the racquets together, my racquet sounded a good bit tighter (despite having a larger head and lower tension).

I decided to go and buy a digital pull scale for my machine, thinking the tension must not be right. I pull the machine to 50# and get something like 50.03 pounds on the digital scale. I try 60#, and am again within 0.1 pound. Ditto for 65, 55, 45, etc... So I truly think the machine is pulling what it is supposed to.

I then get clinical on how I am mounting the racquets -- thinking I may be over-tightening the 6 point brace and squeezing the frame in, putting string in at the correct tension, then releasing that squeeze and effectively upping the real tension several pounds. So I get very careful and just snug the braces very slightly -- as per the Gamma instructions and what others have mentioned here. "Treat the knobs like a delicate egg". Same results.

So I find myself stringing my Radical with a dial-in tension of 44# and find the racquets play great; however, they play comparable to a racquet strung at "50-55 pounds" on other machines.

Also, I'm not pre-stretching, pulling extra tension for tie-off knots, etc.

Am I crazy / what could I be doing so differently to effectively make a "45#" job in racquet play like a "55#" in another machine?

It's not a big deal since I string my own racquets; however, it would be nice to read a review of someone saying String X plays great at 50# in my racquet and not have to guess/wonder how low to go to get the same 50# they reference. As is, I'd start at 10% lower for sure.

Thanks in advance.

 

[Irvin]

How long is the tensioner holding tension on the string before you clamp the string? From the time you start to drop the weight until the time you clamp the string it is stretching. Under a constant tension yes but the longer it is stretched the longer it will be. The longer it is stretched the the lower your string bed stiffness will be. Tension is a number! Find one you like with your stringer and you are home free.

Take for instance a lockout stringer. You pull the same tension with it you pull with any CP tensioner and it will have a lower string bed stiffness. Why? Because you don't stretch the string as long. Continue to stretch the string with a lockout and they will be the same. I think you will find many people say a lockout results in a string bed stiffness 10% lower than a constant pull. BUT if they all pull at the same tension how can that be? The length of time you pull is the answer.

 

[AA5B Tiger]

How long is the tensioner holding tension on the string before you clamp the string? From the time you start to drop the weight until the time you clamp the string it is stretching. Under a constant tension yes but the longer it is stretched the longer it will be. The longer it is stretched the the lower your string bed stiffness will be. Tension is a number! Find one you like with your stringer and you are home free.

Take for instance a lockout stringer. You pull the same tension with it you pull with any CP tensioner and it will have a lower string bed stiffness. Why? Because you don't stretch the string as long. Continue to stretch the string with a lockout and they will be the same. I think you will find many people say a lockout results in a string bed stiffness 10% lower than a constant pull. BUT if they all pull at the same tension how can that be? The length of time you pull is the answer.

I usually can string up my Radical in 30 mins with my drop-weight machine... I typically pull the string, get the lever level, clamp and release tension -- the tension may be "on" 10 seconds or so -- max.

 

[struggle]

perhaps your "pro" friend is not a good stringer.

it is not uncommon. just because one can play tennis well does NOT mean they know how to properly string a racket.

kinda like a race car driver....you think Danica Patrick knows how to rebuild an engine?

 

[Irvin]

Wen I string on my electronic CP the tension is on about 5 seconds. When I use a my lockout the tension is on for about 1 or 2 seconds. When you pull a string the string will resist the change but gradually stretch some more than others.) If the tension is the same the longer you pull the higher the string bed stiffness will be because it stretches farther. This is especially true on the cross strings because you overcome the friction between the mains and crosses.

10 seconds is a long time.

 

[AA5B Tiger]

perhaps your "pro" friend is not a good stringer.

it is not uncommon. just because one can play tennis well does NOT mean they know how to properly string a racket.

kinda like a race car driver....you think Danica Patrick knows how to rebuild an engine?

Maybe so, but I have watched him string on a digital machine, and saw nothing at all questionable in his technique.

Add in too the official range of recommended tension on my Head Radical is 47-57 pounds -- yet I'd treat 47 as an absolute upper limit. Anything above that would be like swinging a 2X4 for me. That too makes me think I'm the problem...

Finally, nearly universally everyone I play uses a good 8-10lbs more tension than I, yet I can pick up their racquets and all feels fine....

If it is me, I truly have no idea what I could be doing wrong... Might just be the unique combination of frame, string, machine, etc. and this can never be an apples-to-apples comparison with others unless they are at least using the same frame/string...

 

[Irvin]

Just did a little quickie test on my Wise which has a lockout feature. I pulled 60 lbs of tension in 5 seconds it dropped to 56.2 lbs and in 10 seconds it dropped to 55.1 lbs. Assuming a CP will maintain the same original tension a 5 second pull would result in a 6.3% greater SBS (3.8 lb/60 lb) and a 10 second pull would have an 8.2% greater SBS (5.9 lb/60 lb.) Neither you nor your friend is doing anything wrong.

 

[AA5B Tiger]

Just did a little quickie test on my Wise which has a lockout feature. I pulled 60 lbs of tension in 5 seconds it dropped to 56.2 lbs and in 10 seconds it dropped to 55.1 lbs. Assuming a CP will maintain the same original tension a 5 second pull would result in a 6.3% greater SBS (3.8 lb/60 lb) and a 10 second pull would have an 8.2% greater SBS (5.9 lb/60 lb.) Neither you nor your friend is doing anything wrong.

Thank you for the test. That has quite a ring of truth to it... I typically just take 10% off what someone else says is a good tension -- and that rough adjustment in my head is pretty close to the measurement you got...

Glad I'm not crazy.

Take care -- and thanks again.

 

[Lakers4Life]

Do you have an ERT or Tension Meter? That would verify if you have some consistency between two machines. Given that you use the same string and tension on the same racket.

 

[Nellie]

For what it is worth, I double pull with my lock out machine (tension once, release, and tension again), and people complain that my string beds are too tight at the specified tension values. I feel like it gives less variability to the string bed.

 

[AA5B Tiger]

For what it is worth, I double pull with my lock out machine (tension once, release, and tension again), and people complain that my string beds are too tight at the specified tension values. I feel like it gives less variability to the string bed.

My take away from this thread is: 1) whatever you do, do it consistently, and 2) tension values are really machine/stringer specific and really don't mean much except to reproduce a desired performance (with the same machine/stringer).

If anything, this thread makes the value of lock-out machines rise in my eyes as the time tension is on the string is so very important in producing consistent/reproducible results. With a drop-weight or constant-pull electric, the tension times on the string become a factor of the stringer -- and if he/I dropped a tool, got a phone call, was just running faster/slower that day, the actual tension put on the string could vary even with the same tension dialed-in.... With lock-out machines, the clutch disengages at the same time, as soon as the target is reached, with an on-tension time being nearly identical everytime... That "consistently reproducible performance" with a lock-out machine, even if it is an effective tension 10% less than other types of machines, would be more valued by me than anything else.

If anything an electronic head with lock-out ability, like the Wise, seems the best -- i.e. no worrying about mechanical degradation of the clutch; instead, an electronic tension scale engages the "clutch" and immediately stops the pull at the same time, every time.

Lots learned today / thanks.

 

[Woolybugger]

This explains why when I did a rush job my stringbed felt stiffer than when I strung leisurely!

 

[Irvin]

This explains why when I did a rush job my stringbed felt stiffer than when I strung leisurely!

Seems like it would be the opposite.