Racquet with designed Non-traditional stringing pattern

Unique stringing pattern for a Hart Infinite OV-3000, the grommet layout facilitates a top-down approach.

Overall view before last row tensioned

Top portion of frame

Bottom portion of frame

Using phone app to monitor string tension (Part-2/2)

Based upon testing using CARLTUNE (IPhone and android), the app will display a frequency of approximately (+/-10Hz) 1144Hz if you hit the sweet-spot on your racquet against the base of your palm, for tension of 22lbs. Basically is the average after several such hits.

Approximate CarlTune reading for 22lbs tension

Verifying tension on the newly strung Yonex Aerosonic

Please perform the action as close as possible to the phone mic for best results. I did discovered the phone can be further away if you are in a enclosed and closed room. In this scenario I try to keep a shuttle in the air gently via tapping, with the app monitoring the Hz of the hits.

Tested the procedure with racquets strung with Yonex Aerosonic (0.61mm), Yonex BG66 Ultimax (0.65mm), Gosen Pro66 (0.66mm) and Ashaway Zymax62 (0.62mm) which seem to provide similar results.

In addition, I had reverified the tension using the Tension-O-Meter since I just restrung one of my racquets with Yonex Aerosonic @ 22lbs - app shows 1144.xx Hz. Sometimes the result would be within a few Hz of the above. Irregardless, the percentage of error would be small and hence negligible for the purpose of (free) monitor facility.

Thus we can use the following simple formula to determine tension via the frequency readout on the app.

1144 Hz = 22lbs

1 Hz       = 22 / 1144

               = 0.01924

Thus a x Hz  readout would mean tension of approximately = 0.01924 * frequency shown on app (tension in lbs)

True this methodology is not 100% accurate as it is meant to provide a means for monitoring, not provide absolutely accurate readings. There are such commercial app and/or tools but they won't be free!

Using phone app to monitor string tension (Part-1/2)

Before I describe my layman version of the authors technique, please assist to review the original article at Badmintoncentral - give credit where credit is due.

They provide a technical in-depth discussion of the technique and the science behind it. 

Do you know how to make use of the information presented to actually monitor the tension on your badminton racquet?

If not, tune back next month and I will reveal how the average Joe can monitor their racquet tension without any expensive tools.

FYI Grommet replacement for Yonex Z-Force 2 (and alike)

Recently had to help a client replace the "in-line" grommets at the upper half of a Yonex Z-force 2, as it seem to be cutting into the string. 

Now for the shocking news - I called the local Yonex distributor as well as various local shops and they tell me to go order the replacement from overseas myself, as they would charge a processing fee for the item.

Why is it shocking, you say? 

If you try ordering it, the "in-line" grommet is not available as a single item. You must buy the entire set of grommets for the Z-Force2 at about USD$12 per set!!! This is before cost for shipping etc.

KUDOS to Yonex for this easy money making scheme!

So owners of the Z-Force2 and some models of ArcSaber/NanoRay/Voltaric be aware of these impending future expenses.

Sweet spot difference on ISO vs box frames

Found the following pix on the net which illustrates the sweet spot difference between a traditional box shape and a modern ISO frame - easier to show using the below than trying to explain it.

Another fake racquet from PRC

A friend recently purchased the following fake from PRC via TaoBao after using my Dunlop Biomimetic Evolution. I purchased my pair in 2010.

The below pix shows the fake with yellow strings - looks ok right? Even the skin effect of the Biomimetic series was well cloned.  Upon closer inspection, there are differences.

1. Racquet is 675mm for the FAKE (YELLOW string) vs 670mm of the original and of the specifications printed on the shaft of both the original and the fake.

2. Finger over the wordings on the frame of the FAKE (YELLOW string) feels lumpy (aka printed) vs smooth feel on the original

3. Smear of the BIOMIMETIC on one side of the frame of the racquet on the FAKE (YELLOW string) vs the original

4. Difference of the cap over the handle

5. Grommet layout of the original vs the FAKE (YELLOW string) which is alike an older racquet I bought in 2009.

Fake version in Yellow string

Closeup of bottom grommets on the fake

Fake (YELLOW string) vs original (BLUE string)

Note the difference in the grommets on the 12th position from the shaft. The grommet layout of the fake is as per normal racquets whilst the original has 2 micro-grommets at the same location.

Grommets at top of frame. Fake in YELLOW vs original in BLUE string

Minimal difference here with the fake (YELLOW string) having only a single large grommet. The original has 2.

More grommets on the side of the original

Both the fake (YELLOW string) and the original (BLUE string) have 6 transparent micro-grommets on each side of the frame. However on the original, there is a additional micro-grommet after the last transparent micro-grommet on the top of the frame.

Difference in string layout - overlay of fake (YELLOW string)  over the original (BLUE string)

String pathing differs on the fale (YELLOW string)

Different handle top of the fake (middle)

Pix of grommet layout of friends racquet from same series. He bought his racquet from Malaysia., Grommet structure is as per my racquets in BLUE and WHITE strings.

"Fake" Yonex?

I have came across fake Yonex racquets before but nothing like this. The other fake YY was copy of the ArcSaber FB which was immediately apparent once you pick it up - feels like the original YY Blacken!

This yellow beastie was another animal altogether. Build quality and finishing material quality was superb.

Physical giveaways were the YY logo at the T-joint, as well as the non-aligned wordings along the shaft.

Feels light for a 3U but handles extreme well, like the real thing.

My take is that it is a real Yonex which failed QA or one which was process "wrongly". Reason is because I believe it is a Voltaric I-Force which was finished incorrectly. When I help string the racquet, the grommets layout reminds me of the I-Force, especially the unique position of the last line to be tension on my stringing machine. I would swear it was a I-Force if it was sprayed black and passed to me for stringing!

I enclose the pix(s) below for your review.