Squash Source

9 responses to “Opfeel SR 990 Control”

1. Tjeerd

   December 28, 2019

   While walking through the Decathlon store in Eindhoven today, one of these babies got stuck in my shopping cart. So, the only option was to buy it (€ 79,99) and bring it home, probably because it reminded me a little of my beloved Wilson Tour BLX 2011/2012. ^_^

   I didn’t play with it yet, but just wanted to share the off-the-shelf figures:

   Racket weight: 155.0 grams
   Racket balance point: 34.2 cm
   Calculated swing weight: 157.9 kgcm2

   The frame feels quite stiff. I’m not sure, but it seems to be strung with a decent quality synthetic gut and the factory string job looks and feels consistent; I’ve seen much worse on high end brand rackets..

   So far so good, looks like good value for money. Will keep you all posted as soon as I play tested this racket.

   Reply
   1. Pierre

      December 30, 2019

      Thanks Tjeerd I added those specs. Very head light! How did you calculate the swingweight?

      Reply
      1. Tjeerd

         January 1, 2020

         First of all I want to wish you, and everybody else reading this this site, the best wishes in good health for 2020!

         To answer your question, Pierre: first I measure the head & grip weight using two identical kitchen scales.

         Next, I enter the numbers in this Stringway Online Swingweight Calculator, that will spit out the calculated swingweight. It’s basically a type of moment of inertia calculator, probably combined with some corrections in an effort to get the outcome as close as possible to real swingweight measurement devices, like the Prince Precision Tuning Center.

         I also have the formulas behind this calculator in a handy Google Sheets document, combined with some tooling to do your own swingweight tuning. I’ll be happy to create a blank copy of it, to share with everybody out here. 🙂

         Reply
         1. Pierre

            January 2, 2020

            Happy new year! Very cool, so with the two scales, do you just lay the racket on them flat and they will give you a slightly different reading usually, and that is what gets entered in the calculator? Might have to get myself a second kitchen scale…

            Reply
            1. Tjeerd

               January 3, 2020

               You do not need 2 scales; with a single scale, I simply use some whiteboard magnets to keep the racket nicely flat / horizontal and weigh the head and grip separately. Just enter the numbers (racket length is usually 66.8 cm) and you will get the balance point as accurate as it can get, and the swingweight as a bonus. 🙂
         2. Nick

            January 3, 2020

            A typical squash racket is 68.6cm, not 66.8cm as you used.

            I found that site as I was curious about swingweight. I could only use the weight/balance point calculator on the page, as that’s the only information you posted, but came up with a different figure originally because of the different length used. Using 66.8cm instead, I get much closer to your original figure (157.64 kgcm2).

            Reply
            1. Tjeerd

               January 4, 2020

               In my stubbornness I re-measured a couple of my rackets and you are absolutely right, Nick; they were all 68.6 cm. In fact, you uncovered that I was systematically using this incorrect racket length! (insert facepalm here…)
               So, may thanks for your comment!

               Hereby the revised and complete numbers:

               Head weight: 79.4 grams
               Grip weight: 75.6 grams
               Racket weight: 155.0 grams
               Racket length: 68.6 cm
               Racket balance point: 35.1 cm
               Calculated swing weight: 168.4 kgcm²

               I had a hit with this racket yesterday, and I must admit that the number above, better match up with how this racket felt to me on court: light and evenly balanced. The racket played quite nicely: good control, almost no vibrations and no troubles at all to hit a decent length. The stringbed felt a bit dull and damped, but I am sure stringing it up with a higher quality string will give it a boost in liveliness.

               For me, this racket is a keeper!
   2. Tor

      January 24, 2020

      Been swinging it on court yet? 😊

      Reply
      1. Tjeerd

         January 31, 2020

         Hi Tor,

         Yes, I had a quick swing with it on court, after I restrung the racket with a low-budget multi filament string. Although it was a low budget string, it was definitely an upgrade compared to the factory string, that made the racket more responsive.

         Next thing I want to try, is to restringing it with an higher end multi filament string; probably Dunlop Silk 1.18 or Kirschbaum Multifibre Touch 1.15.

         Reply