i have in my hand 3 identical brand new Yonex rackets. of the same brand, model, weight, grip size (2UG5). none of them have been strung/played, and even the grip wrap are intact.

i gathered this is a good time to make some measurements of them to gain some insights on the quality consistency in Yonex manufacturing.

the 4 data points are the gross weight of the racket, the weight of the racket head with the handle rested on the table, and vice versa, as well as the balance point.

the measurements are done on a scale with 0.05g precision.

as you can see, there are a certain variation with the weight and balance of the rackets. almost 3g on a 90-95g racket, that's 3% variance. racket A/B are quite similar while racket C seems to be particularly lighter on the racket head and thus more even balanced.

the data will be more representative if we have many many more racket but unfortunately, that is not very feasible.

anyway, here are the data:

as you can see, there are a certain variation with the weight and balance of the rackets. almost 3g on a 90-95g racket, that's 3% variance. racket A/B are quite similar while racket C seems to be particularly lighter on the racket head and thus more even balanced.Tut, tut
:rolleyes: 3g equals 3% variance? High school maths teachers are going to be after you! :p

I am wondering how did you determine the handle weight and the head weight?
Because for instance, Racket A is 93.10g. But the handle + head are 90.95g. So, where did the rest of 2.15g go? all in shaft? (I think shaft will be probably heavier than that, right?)

Forgot to ask, are they the same batch? ie.e serial numbers similar?

Tut, tut
:rolleyes: 3g equals 3% variance? High school maths teachers are going to be after you! :p

ops.... i think i am safe, i have strategically placed all my high school teachers at least one ocean away from me... ;)

I am wondering how did you determine the handle weight and the head weight?
Because for instance, Racket A is 93.10g. But the handle + head are 90.95g. So, where did the rest of 2.15g go? all in shaft? (I think shaft will be probably heavier than that, right?)

as mentioned, the head weight was determined by resting the handle on the table, and vice versa. as the table / scale are not in the same level (vertically), one cannot simply add the two weight/forces together.

Forgot to ask, are they the same batch? ie.e serial numbers similar?

not sure as these are old serial number rackets and there is a hologram sticker over the engraved serial. some of them don't belong to me so i didn't remove the hologram to look.

Should we also do a stiffness consistency test?

Should we also do a stiffness consistency test?

one of the racket belongs to you. do you want me to do it? ;)

Haha, let's wait then. :D

one of the racket belongs to you. do you want me to do it? ;)

Kwun, all new Yonex racquets come with clingwrap over the handle, which can weigh anything from 0.5gm to 1.2gm. Did you unwrap them before weighing on the scale?

I think the grips are all dried out and the clingwraps have fully glued into them. Taking off the clingwraps will destroy the original grips.

Kwun, all new Yonex racquets come with clingwrap over the handle, which can weigh anything from 0.5gm to 1.2gm. Did you unwrap them before weighing on the scale?

I think the grips are all dried out and the clingwraps have fully glued into them. Taking off the clingwraps will destroy the original grips.

No, if new Yonex racquets are stored carefully. I have had no trouble taking off the clingwrap from all new Yonex racquets that I have bought. However, some Taiwanese and Chinese racquets do have trouble with the clingwraps that do not come off. The reason is simple : these manufacturers apply too much blow heat on the clingwrap at the factory, fusing the clingwrap with the grip. Yonex QC is much better, and they apply the appropriate temperature blow heat. :D

These are very old racquets taken out of the storage bin so to speak ;)

Are you sure you are not working for Yonex? You seems to know a lot about their QC and production and so on. :)

No, if new Yonex racquets are stored carefully. I have had no trouble taking off the clingwrap from all new Yonex racquets that I have bought. However, some Taiwanese and Chinese racquets do have trouble with the clingwraps that do not come off. The reason is simple : these manufacturers apply too much blow heat on the clingwrap at the factory, fusing the clingwrap with the grip. Yonex QC is much better, and they apply the appropriate temperature blow heat. :D

Hm. So these racquets are all "new from old stock"? Exactly how old? It would be interesting to compare with "new from new stock" racquets, to see if manufacturing methods are more consistant now...

A variation in overall weight of 3 g is not so unexpected. I don't think a human could tell the difference (if it's evenly distributed that is). After all Yonex does claim that 2U is 90-94 g. I always thought that the interval was there to allow for variation between models, but now we know the truth... It's because thay can't make two racquets the same! :rolleyes: ;)

What is more disturbing is the variation in balance point. 5 mm difference is quite a lot, and would certainly affect racquet feel.

Kwun, all new Yonex racquets come with clingwrap over the handle, which can weigh anything from 0.5gm to 1.2gm. Did you unwrap them before weighing on the scale?
no. but i made the assumption that they all weigh the same. i wasn't interested in the absolute weight of the racket but instead the difference in weight. furthermore, some of the rackets i bought on behalf of my friends, so i think it was important to give it to them in the original condition.

Mag, they are new old stock. the old serial number means that they are at least from 1999 if not before that.

Shiiiii, let's not stir up the CP/CN VS SP & TH thingy again. :D :D :D

Hm. So these racquets are all "new from old stock"? Exactly how old? It would be interesting to compare with "new from new stock" racquets, to see if manufacturing methods are more consistant now...

A variation in overall weight of 3 g is not so unexpected. I don't think a human could tell the difference (if it's evenly distributed that is). After all Yonex does claim that 2U is 90-94 g. I always thought that the interval was there to allow for variation between models, but now we know the truth... It's because thay can't make two racquets the same! :rolleyes: ;)

What is more disturbing is the variation in balance point. 5 mm difference is quite a lot, and would certainly affect racquet feel.

Shiiiii, let's not stir up the CP/CN VS SP & TH thingy again. :D :D :D


i highly doubt those 3 rackets are cp/cn verisions.

I can even guess what are those rackets are too :p

They are not CP/CN versions but the point is that someone will say, "I told you so." One camp will say that the great differences in balance point and weight suggest some some batch is more solid than another. Hence, we get the CP/CN VS SP & TH argument again.

Come on Cooler, let's blow the lit off. Take a guess. ;)

i highly doubt those 3 rackets are cp/cn verisions.

I can even guess what are those rackets are too :p

Come on Cooler, let's blow the lit off. Take a guess. ;)

Nah, look like u guys want to keep them undisclosed so i won't alter that...
even though i already know right after the first post :p

what rackets
which version
what price paid
and which shop too :p :p :p LOL

They are not CP/CN versions but the point is that someone will say, "I told you so." One camp will say that the great differences in balance point and weight suggest some some batch is more solid than another. Hence, we get the CP/CN VS SP & TH argument again.

well, the thread's purpose is solely to investigate how consistently rackets are manufactured by Yonex. although i do admit the idea did spring from the CN/CP debate, it wasn't the intention of the thread. the consistency study in itself is quite interesting already. what it tells is that if you buy two rackets of the same model, it is not guaranteed that they are identical.