There has been a lot of talk about the Badminton racket selector on DirectSports either emails or calls to us, talk on forum sites questioning why our racket specifications are different to the manufacturer specifications. So I have decided to write a little bit about it to explain why it was created, how we set the values and what we are aiming for.
We decided that there needed to be a system to compare all the rackets in an equal setting. An independent measure across all brands allowing customers and our staff (we play too) to make a more informed choice about which racket to buy and the actual way they will feel rather than having stock specifications. Each manufacturer supplies the information differently so some may not weight the racket with a grip, others do. By setting up the racket selector we have created an equal field so it is easier to compare between brands and make informed choices.
- Babolat seem to specify that all of their rackets are very flexible and they are compared to a Babolat Tennis racket, but in Badminton their rackets fit into the standard range.
- Racket information supplied to us and online is normally for an unstrung frame only, I need a handle, grip and strings to play, so the weight and balance is different when they are added.
The most basic measure that we use is a simple accurate digital set of scales. I aim to take an average of 3 measures, it normally shows up the same each time as we bought some expensive scales; where available I will weigh 3 of the same rackets and take the average over the 3 to account for differences in manufacture tolerance.
We only weight the racket with strings in, without plastic handle wrap, it makes a difference of about 8g. 8g could be 10% of the total racket weight, which is just forgotten about.
When measuring flexibility there are two options – measure static flex using a known force and measure the distance the head moves or dynamic flexibility checking the movement of the racket during a swing on impact with the shuttle. Dynamic flexibility is a better measure of racket performance as the racket is moving when it impacts with the shuttle, but it is subject to variables such as racket movement speed and shuttle speed. Some materials manufacturers develop claim to add flexibility or harden during play and this would need to be measured dynamically. Until I find a way to keep the racket speed and shuttle speed constant to allow a fair test on all rackets I will be using the static flex method as it can provide a fair comparison.
The racket is held horizontally in a vice with a steel bar over it. A known weight is added to the top of the frame and the movement in distance from the steel bar is measured. It is repeated 3 times to enable an average to be taken.
Balance is measured as the distance from the base of the handle to the point the racket can be held horizontally without tipping in either direction. The racket should be completely parallel with the floor. I use a piece of steel tubing attached to a ruler, simple but effective. The steel tube is smooth and rounded meaning a precise balance needs to be achieved before a measure is taken. It is measured from the base of the handle to the balance point up the shaft.
A low value of 290mm would be a very headlight racket as it doesn’t take much of the handle and shaft to counterbalance the shaft head and strings. Medium balance tends to be around 300mm away from the base and head heavy 310mm.
There are ways to modify the balance of a racket which I will blog about soon in racket modifications.
Feel Free to leave comments and questions and I’ll get back to you as soon as I can.
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