08-03-2009, 06:17 AM #18
Hi Kwun, thanks for the very helpful article. Anyway, I am an intermediate player and used to play 2-3 hours a day and 4-5 days a week. Currently I am using the string tension at 27lbs at my KX 929D. I totally agree with your article on the grip size and the string tension. The only thing that I still don't understand is that whenever I used the lower tension below 23lbs, my smashing power is deteriorating. Most of the people that I met, they often said that they can't even smash using my racket BUT it also goes the same to me when I used their racket with lower tension. Is there any explaination on my scenario. Please advice... rgds
08-13-2009, 07:38 AM #19
Really a good article! Should benefits most of the green hands~
09-17-2009, 02:16 PM #20
I'm a new comer of the forum. I fully agree with the opinions of Kwun. Thank you!
12-04-2009, 08:09 AM #21
I wished I read this first. Because I started playing badminton a few months ago and I was using running shoes, yup I strained my ankle! So I imediately bought myself a proper badminton shoes and no problem since!
12-12-2009, 10:55 PM #22
just one minor point..
i think for clothing, cotton is not so good... it's sticky... 100% polyester (without any cotton) is best...
12-12-2009, 11:12 PM #23
I think clothing is really a matter of personal preference. I myself hate polyester because they (gasp) make my nipples really sensitive and painful. (true story) so I really prefer 100% cotton.
12-13-2009, 12:22 AM #24
Yonex do have some shirts and shorts, although 100% polyester, which is silk smooth...
01-28-2010, 09:50 PM #25
I could not agree with "kwun" more on the right shoes. I am a newbie to badminton played, as a child in the playground. I am a decent golf and tennis player but my daughter loves badminton so I decided to take it up . She represent her primary school, P6 but i can still beat her .. not sure for how long though . I bought a pair of yonex mid range shoes 60$ and had a horrible experience. As a 48 yr old I can't affprd injuries and got myself a SHB101 recently, what a difference that made !
Now i am wondering if the rackets will make that much of a difference , I am using my daughter Proace 9000 a copy of the Yonex. I found its head too light. I am wondering if there is a big difference between a flymax 900 and Yonex 900 ? the price difference is 1/2. And at my level I wonder if it makes any difference. And who is Flymax? cannot find it on the net.
appreciate any advice.
11-01-2010, 12:13 AM #26
05-09-2011, 02:40 PM #27
10-02-2011, 09:43 PM #28
Badminton Racquet Selection Factors
Thank you Kwun and other contributors. Many people ask me for guidance to help them select a racquet so I've compiled this essay. As Kwun points out, there are probably more important pieces of kit in your bag (your shoes, for example), but racquet selection is certainly a high cost and confusing decision. There are lots of differing views on how different racquet design features may affect your game. A search of the web will inundate you with information, but unfortunately much of it is inconsistent and some of it is just downright nonsense. The racquet manufacturers themselves aren’t much help – their sales information is very heavy on fancy pseudo-science and very light on facts. So I’ve collected information (some from badminton central), done some engineering calculations, some thought experiments and some actual experiments and I have come up with this guide. This is not a guide to picking one manufacturer over another, or one racquet model over another; it is intended to arm you with knowledge of how a number of key racquet design features might affect your game. The design features I’ve chosen to address are: weight, balance, frame materials, frame stiffness, string selection, string tension, grip size, racquet length, head size and “other” racquet design features. I can’t claim to have all the answers and I’m hoping this essay will generate a healthy debate! So, on that note, I’ll start with the most contentious and most confusing design characteristic:
Yonex (and most other racquet manufacturers) use this scale to specify the weights of their racquet models:
1U – 95-100g
2U – 90-94.9g
3U – 85-89.9g
4U – 80-84.9g
5U – 75-79.9g
These weights are for a racquet with a standard supplied grip and no string. Note: many players add aftermarket grips…and all players add strings!
Most of us play with 3U or 4U racquets (Yonex Arcsabre’s, Nanospeeds, Armortecs…).
The lighter the racquet, the more maneuverable it is and the easier it is for the player to accelerate it in the swing (all other things being equal).
A heavier racquet will be more stable on impact (giving better control/accuracy) and transmit less shock to the player than a lighter racquet (all other things being equal).
A heavier racquet will also transfer energy more effectively to the bird. This would be rather significant if birds were heavy, but the bird actually weighs just 5 grams so the racquet is between 15-20 times heavier than the bird. Small differences in the racquet weight will have a relatively small effect on energy transfer.
Conventional wisdom says that heavier is better for power, but it clearly isn’t as straightforward as that or we’d all be playing with huge heavy racquets. Clearly, the power a racquet generates depends on a combination of its weight and how fast the player can swing it. Will a lighter racquet that is swung fast generate the same or more power than a heavier racquet that’s swung more slowly? I’m not sure. There may be an optimum weight/balance for a particular player’s physical attributes. More on this, after I’ve discussed the sister characteristic to weight…
Aside from the weight of a racquet, the balance of the racquet (where the weight is positioned in the racquet) is also very important. How heavy a racquet feels in the swing will depend less on its weight than where the weight is balanced.
Nerd alert! Rotational inertia is proportional to moment of inertia, which is itself proportional to the square of the distance of the center of inertia from the pivot center. What this means is: If your 85 gram racquet balances at 28 cm from the handle end, it will require about the same force to accelerate it as a 75 gram racquet that balances at 30 cm from the racquet end. In this example, the 85 gram racquet is 13% heavier than the 75 gram racquet, but will “feel” very similar in the swing.
So where does that leave us? Do you want a lighter or heavier racquet and should it be head-light, head-heavy or evenly balanced? Well, most experts seem to suggest:
Head-light racquets are very maneuverable for quick rallies but they are designed for players who provide their own power - players that have good shot production and generate high racquet head speed.
Head-heavy racquets are less maneuverable, but may provide more control (the head moves less on impact) and the head will transfer more power to the bird. Heavy racquets also reduce shock transferred to the wrist and elbow, which some players appreciate.
Aside from your own specific shot production abilities, you should also consider the use to which you put the racquet. Level doubles (e.g. men’s doubles) is mostly about quick shots and hard smashes, singles (and to some extent mixed doubles) is more about control (hitting all four corners of the court).
The best way to select the right weight and balance is to try lots of racquets and find one you like. If that’s not an option, or you can’t decide, buy a medium weight (~85 gram) racquet with a medium balance.
It is interesting to note, however, that racquet weights have gone inexorably down as materials technology has made this possible. Note: the material used in the racquet handle (wood) has changed little over the years so racquets have also become more head-light. My theory is that lighter racquets are fundamentally better than heavier racquets. Controversial for sure, but here is my “trend analysis” thinking: I was playing in the early 1970’s with the same 125 gram racquet that the world champion used, we could have been playing with the new (at the time) 115 gram racquets just coming onto the market, but we convinced ourselves that these new racquets were just too light. By the early 1980’s I was now playing with the same 115 gram racquet that the world champion used, we could have been playing with the new (at the time) 105 gram racquets just coming onto the market, but we convinced ourselves that these new racquets were just too light. By the early 1990’s I was now playing with the same 105 gram racquet that the world champion used, we could have been playing with the new (at the time) 95 gram racquets just coming onto the market, but we convinced ourselves that these new racquets were just too light. By the early 2000’s I was now playing with the same 95 gram racquet that the world champion used, we could have been playing with the new (at the time) 85 gram racquets just coming onto the market, but we convinced ourselves that these new racquets were just too light. OK, you get the picture, most of us are now playing with 85 gram racquets and most of us say that the new generation of 75 gram racquets are just too light! Well, I don’t agree. I love my Black Knight Superlight (75 grams) and I predict that in a few years most of us will be playing with 75 gram racquets (and a few early adopters will be using 65 gram racquets). Whatever the science says, the trend is hard to argue against – in general, lighter is better!
Much is made in the manufacturer’s sales brochures about the materials they use. Graphite, titanium, ultra-high modulus nanotubes and many more colorful descriptions feature heavily. These materials do indeed contribute to the performance of a racquet; however, it is the particular characteristics we are looking for, not the material. Most good quality modern racquets (and all seven of the racquets in my bag!) are one-piece (no separate “T-piece”), carbon composite construction. Carbon composite has remarkable strength-to-weight and stiffness-to-weight characteristics which make it ideal for racquet construction. Carbon composite is also known by other names such as: carbon fiber, graphite fiber, carbon fiber reinforced polymer/plastic…and in a modified form as carbon graphite fullerene stacked nanotubes etc. The problem with carbon composite is that it has lower fracture toughness than the metallic alternatives. The old aluminum, titanium and steel racquets could withstand a hearty beating, but as many players have discovered, one sharp clash of carbon composite racquets and your $200 weapon is heading to the trash!
As an engineer, I think it is pretty cool that the badminton community is a “first adopter” of cutting edge materials technology, but much of it is marketing over substance. Whether the racquet uses carbon fullerene nanotubes (a truly exciting development in polymer science) or aluminum doesn’t matter a jot; what’s important is how the racquet performs. I recommend that you do not base your racquet selection decisions on the materials, rather select your racquet based on its weight, balance, stiffness, durability and other key performance characteristics. If you follow this advice, I suspect you’ll end up with a one-piece carbon composite racquet….and if fragility is a major concern, you’ll buy a $50 model rather than a $200 model!
The amount a frame deflects during shuttle contact directly affects its power potential. A stiffer racquet bends less, thus depleting less energy from the bird. A common myth among players is that a flexible racquet, that bends back more, returns more power to the bird due to a catapult-effect; I doubt this very much. During a normal stroke, the racquet accelerates all the way to the bird so any flexure in the racquet will store the players swing energy, and since the bird remains on the strings for a small fraction of a second, the stored energy will only be recovered after the bird has left the strings and the player is in their follow-through. I believe that under most circumstances, a racquet frame doesn’t “return” energy to the bird, it absorbs energy - either more or less, depending on stiffness. I suppose it may be possible, with some strokes, for the racquet to be decelerating at it hits the bird, in which case the energy stored in the shaft may be returned and contribute to the power of the shot…but it would be a rather strange shot and I can’t image that it would generate as much power as accelerating all the way to the bird (shoulder-arm-pronation-fingers). So I’m convinced that stiffer racquets don’t absorb as much swing energy resulting in less power drain than a flexible racquet. Stiffer racquets result in more power. Nerd alert: there is an argument that centrifugal and torsional acceleration stiffening diminishes the racquet’s effective flexibility during the stroke, but the principle still holds: stiffer frame = less loss of power during impact.
By deflecting less during impact, stiffer racquets should also give better control (accuracy), particularly on power shots (smashes, clears, drives) and when the bird hits the strings off-center.
Frame stiffness doesn’t only affect power and control though. “Feel” and comfort are also at stake. Some players find that stiff racquet don’t provide as much “feel” on touch shots and stiffer racquets may be less comfortable than more flexible racquets - a very stiff frame will transmit more impact shock to the wrist, elbow and shoulder than a more flexible frame.
Adult racquets are available in lengths ranging from 66 to 68 cm (the legal limit). Older and less expensive racquets are 66 cm long, modern more expensive racquets are 67.5cm long and a few are the maximum 68 cm. A longer racquet provides slightly more reach and slightly more leverage and therefore slightly more power (all other things being equal). Of course, all other things are often not equal – longer racquets need to be lighter to avoid them feeling too head-heavy in the swing.
The string manufacturer’s sales information is as loaded with fancy pseudo-science as the racquet manufacturer’s brochures. I’ve studied these string brochures. They outline the Repulsion Power, Durability, Shock Absorption, Control, Feel, Speed, Wind Resistance and even the quality of the Hitting Sound! There are even attempts to show the relative merits of each string model on a particular player’s game…but I just don’t buy it. The material/composition of a string will affect its properties, but I don’t believe that these properties will trade off in as neat a way as the manufacturers claim. Why would a string with high repulsive properties (bounce) be necessarily bad for control (accuracy)? It’s also not at all obvious to me why a “hard hitter” would want a high repulsion string to the detriment of control. I can see how thinner gauge and rougher micro texture string would result in reduced durability (compared to thicker gauge, smoother string), but I suspect that the many variations in string materials/construction are second order effects compared to string tension. Here’s how I think of it…two piano wires are made from the same extremely stiff material (steel) and they produce a totally different response (musical note) as they are tuned. In fact, it would be possible to loosen one of these piano wires until it was quite useless (incapable of resonating) and tighten one until it was quite useless (it resonates above the range of human hearing)…all without altering the string material or composition. String tension is more important than string material. Of course, nobody makes money out of “string tension” (stringers charge the same whatever you ask for!) so we find ourselves distracted by a discussion of string materials, composition, manufacturers and models.
For this reason, I’m not going to get into this subject very deeply here. If you want to investigate what Yonex claims for its many string models, go to: http://www.yonex.com/badminton/webcatalog2011/#page=31
I suggest that the most important aspect of string selection is consistency (use the same string across all the racquets in your bag) and durability (to minimize how often you’re without your favorite racquet!).
Racquet string tension can have a profound effect on the performance of a racquet and it is important to understand the basic trade-offs between power and control in relation to string tension.
The racquet manufacturers recommend various string tensions, but most fall into the range 18 to 26 lbs (8 to 12 kg). For beginner and intermediate players, string tensions of 18 to 22 lbs are recommended; advanced players may use 22 to 26 lbs. Professional players may exceed these upper limits, but when we talk about low or high tension, it makes sense to confine ourselves within the range 18 to 26 lbs (not least because exceeding the limits may invalidate manufacturer warranties).
The higher the tension on the frame the more fragile the string and string breakage becomes more likely. High string tension will also increase the stresses on the frame and may possibly make the frame more susceptible to failure (due to shuttle or partner racquet impact).
Within the recommended tension range, the maxim is: lower tension gives more power and higher tension gives more control.
The key to understanding the reason that lower string tensions yield more power is to compare the energy return offered by the strings to that offered by the bird. If you drop a bird to the floor, as the bird hits the concrete, part of the cork compresses and stores energy, which is then released as the bird uncompresses. If all of that energy were stored and released with perfect efficiency, the bird would bounce right back to close to the height it was dropped from (exactly that height in a vacuum). But in fact the bird dissipates a very high percentage of its energy and bounces just a few inches. The strings, however, are designed to return the energy they absorb. In fact, they return around 90% of the energy to the bird (I did some experiments!). When a bird collides with strings, both deform to some extent. The more the strings store the energy of the collision by deforming like a trampoline, the less the bird stores energy by deforming. To get the most energy return out of the collision, we want the strings to store as much of the total energy as possible, because they will give back 90% of it, whereas if the strings were as hard as concrete most of the energy stored in the bird will be wasted. Looser strings deform more easily, thus storing more of the energy of the collision and minimizing the amount wasted in the cork of the bird.
At this point, looser strings sound ideal, so why do looser strings cause a loss of control?
As the looser string bed compresses more, the bird stays on the strings longer, during which time any tiny changes in your racquet position can change the path of the bird. Any unintended movement that occurs, especially when an off-center hit exerts a turning force on the racquet head, will result in a less accurate shot. If you don't hit particularly hard or close to the lines and thus don't need especially precise control, looser strings make sense. If you have power to spare and hit close to the lines, tighter strings are probably your better choice. Professional players use very high string tension!
By absorbing and returning energy to the bird more efficiently, looser strings will also reduce the impact shock transmitted through the racquet and into your body.
One last issue with string tension. Some players choose to string their racquets with asymmetric tension, i.e. with more (~1 or 2 lb more) tension in the short cross strings than the long main strings. Despite having different lengths, the tension carried by the string is the same along its entire length, whether short or long. I haven’t really been able to convince myself of the merits of asymmetric stringing tension, but Yonex does recommend 1 or 2 lbs more on the crosses, so that’s how I string my racquets.
Another complication is that not all stringing machines deliver the same end result. My advice is to find a stringer you trust and over time find the tension that suits your game (my stringer is Poppy and I use BG65 at 20 lbs on the mains and 21 lbs on the crosses).
For reasons similar to the lower string tension providing more power, a larger head will provide more power than a smaller head (all other things being equal). A larger head also offers a larger hitting area and sweetspot, providing more forgiveness on off-center hits. Some expert players prefer a smaller head (they may claim less air resistance or better “feel”) but I endorse the large headed racquets (the Yonex “Isometric” shape or even the slightly larger Black Knight head works for me). Interestingly, while most racquets are at or close to the maximum length allowed in the Laws of badminton, no racquets currently on the market are as wide as the regulations allow (23 cm). Based on a similar trend analysis argument as the “lighter is better” justification (and notwithstanding one or two notable trend-bucking models like the Z-Slash) I suspect we’ll see larger headed racquets becoming more prevalent as materials technology makes this possible.
The grip may seem like a minor matter, but it is where the player interfaces with the racquet and for me, it is a very important factor impacting my appreciation (or not) of a racquet!
Grip diameters are designated with a “G” number: G1, G2, G3, G4 & G5. The problem is, manufacturers aren’t consistent in how they relate these designations to actual grip size! The circumference of Yonex racquets handles (with the standard leather grip) are:
Yonex G2 - 4.00 inches (i.e. large grip)
Yonex G3 - 3.75 inches
Yonex G4 - 3.50 inches
Yonex G5 - 3.25 inches (i.e. small grip)
Other manufacturers inverse this designation (i.e. G5 is large and G1 is small)
In the US, most racquets are sold with a small grip; players desiring a larger grip are effectively forced to add aftermarket overgrips to increase the grip size.
Grip size is a matter for individual playing style, but I have noticed that expert young players tend to use small grips, which they hold extremely lightly and generate a lot of power with their fingers, yet many older players gravitate towards thicker grips and use less finger power. I’m not sure if this is a result of bad technique, bad habits or a physiological result of getting old!
There is also some anecdotal evidence suggesting that changing grip size (either from large to small OR small to large) can help alleviate a bout of “tennis elbow”.
There are countless different aftermarket grips available with differing textures, sweat absorbency and comfort. I suggest you pick the grip you like and then make sure all your racquets are prepared the same way.
There is also a trend on modern racquets to have longer handles (that is, the handle extends further up the shaft towards the head). These longer handles facilitate the player “choking” down the racquet length for certain shots (e.g. the serve and net kills).
“Other” racquet design features
The racquet manufacturers have countless other frame design features they claim will give you an edge. Lower cross section frame profiles may be plausible (reducing air resistance), but many of these features range from dubious to just plain silly (“tuned” head weights to enhance the sound of shuttle impact…hmmm). I wouldn’t base a racquet selection on any such features.
One final point: If you are at all serious about playing competitively, you should have more than one racquet – same or similar model, same grip and same string tension. The worst situation is to be in the third game of a tournament match, break a string/frame and then have to borrow a racquet (different weight, grip, tension…).
04-22-2013, 10:37 AM #29
Very Good post than you
04-22-2013, 10:38 AM #30
Very Good post thank you
05-06-2013, 07:30 AM #31
great info, thank you guys VERY much!
one more thing though, I find that because I only play once a week, my shoes lose their grip after a few months but the shoes are otherwise in tact. Is there anyway I can maintain shoes as opposed to buying new ones when the old shoes basically become rollerskates?
05-06-2013, 09:02 AM #32
05-06-2013, 09:18 AM #33
05-06-2013, 09:26 AM #34
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