e1.  ‘Harimoto Tomokazu InnerForce ALC’ and ‘InnerForce Layer ALC’

Harimoto 01
Fig.01 Butterfly ‘Harimoto Tomokazu InnerForce ALC’

Butterfly ‘Harimoto Tomokazu InnerForce ALC’ is famous as the blade of Harimoto Tomokazu who is the MS winner of 2018 ITTF World Tour Grand Final. (Because its name is too long, it will be called as ‘Harimoto ALC’ in this article.)

Butterfly InnerForce Layer ALC 01
Fig.02 Butterfly ‘InnerForce Layer ALC’

‘Harimoto ALC’ (= ‘Harimoto Tomokazu InnerForce ALC’) is known as the ‘InnerForce ALC’ with bigger head and special graphic design for Harimoto Tomokazu. Butterfly home page is explaining that there isn’t any difference between ‘Harimoto ALC’ and ‘InnerForce Layer ALC’. Equal thickness (6.0mm), equal weight (90g) and equal elasticity (10.7 in Butterfly measure). However, many players who have tried both of those two are saying that ‘Harimoto ALC’ is heavier and faster than ‘InnerForce Layer ALC’.

Harimoto 03
Fig.03 ‘Harimoto Tomokazu InnerForce ALC’ (left) and ‘InnerForce Layer ALC’ (right)

We can hardly distinguish two blades from above picture because those two look almost identical. However, the measured thicknesses are not identical. The average thickness of ‘Harimoto ALC’ is 5.92mm. But, the average thickness of ‘InnerForce layer ALC’ is 5.80mm. And, the average weight of measured pieces of ‘Harimoto ALC’ is 93.8g, while the average weight of measured pieces of ‘InnerForce Layer ALC’ is 86.6g. ‘Harimoto ALC’ is apparently bigger, thicker and heavier.

Harimoto 04
Fig.04 ‘InnerForce Layer ALC’ and ‘Harimoto Tomokazu InnerForce ALC’

Therefore we can easily expect that there will be more than the difference of thickness. In general, if the constructions of two blades are very similar to each other, thicker and heavier one is faster (= more elastic). Because ‘Harimoto ALC’ is thicker and heavier, it will be faster than ‘InnerForce Layer ALC’. That prediction coincides with the experience of players. And, ‘Performance Indices’ will provide us further backup of that prediction.

As always, let’s examine the characteristics of ‘Harimoto ALC’ by ‘Performance Indices’ and compare it with ‘InnerForce Layer ALC’ and some other models.


2. Blades to be compared

Following blades will be compared in this article.

  • Butterfly Harimoto Tomokazu InnerForce ALC (Butterfly Harimoto ALC)
  • Butterfly InnerForce Layer ALC
  • Butterfly InnerForce Layer ZLC
  • Butterfly Timo Boll ALC (Outer fiber, ALC)
  • Tibhar Cedric Nuytinck (Outer fiber, ZLC)
  • Butterfly Korbel (5-ply wood)
  • Stiga Allround Classic (Reference)


‘Harimoto ALC’ and ‘InnerForce Layer ALC’ are very similar to each other in blade construction. Both of those are inner ALC blades with Limba top layer. The main issue of this article is the comparison between those two blades.

‘InnerForce Layer ZLC’ is an inner ZLC blade with Limba top layer. It is very similar to ‘InnerForce Layer ALC’. But, the difference of fiber makes difference characteristics.

‘Timo Boll ALC’ is not an inner fiber blade. It is the representative of the blades with ‘outer fiber’ construction. Its fiber is same as that for ‘Harimoto ALC’ and ‘InnerForce Layer ALC’.  However, its fiber is placed directly under top layer. We can call that kind of construction as ‘outer fiber’ construction. In this comparison, ‘Timo Boll ALC’ is the only one blade whose top layer isn’t Limba. The top layer of ‘Timo Boll ALC’ is Koto.

‘Cedric Nuytinck’ is another blade with ‘outer fiber’construction. But, differently from ‘Timo Boll ALC’, its fiber is ZLC.

‘Korbel’ is the representative 5-ply wood offensive blade with Limba top layer. .

Finally, ‘Allround Classic’ is the representative of traditional all-round blades. And, it is the reference blade of Performance Indices in TTGear Lab. All indices for ‘Allround Classic’ is 1.0.

Harimoto 05

Comparison will be done by performance indices. Concerning the detail of four performance indices, please refer to following articles in ‘Background’ section :


3. Comparison by Performance Indices

Harimoto 06 G01
Fig.06 Comparison by Elasticity Indices

Fig.06 shows the comparison graph of Elasticity Indices

Ep (Primary Elasticity Index) is directly concerned with the rebound speed of blade. Ec (Central Elasticity Index) is concerned with additional ‘kick’ when player hits ball very hard.

From the graph, we can notice that the elasticity of ‘Harimoto ALC’ is apparently higher than that of ‘InnerForce Layer ALC’. Ep and Ec of ‘Harimoto ALC’ are 2.10 and 1.80 respectively. On the contrary, Ep and Ec of ‘InnerForce Layer ALC’ are 1.62 and 1.45 respectively. It means that ‘Harimoto ALC’ is much faster than ‘InnerForce Layer ALC’.

The overall elasticity level of ‘InnerForce Layer ALC’ is a bit higher than that of ‘Korbel’. However, ‘Harimoto ALC’ is a blade in another elasticity level. The elasticity level of ‘Harimoto ALC’ is even higher than that of ‘InnerForce Layer ZLC’. The blades who have similar elasticity level as ‘Harimoto ALC’ in this comparison are two ‘outer fiber’ blades – ‘Timo Boll ALC’ (Ep = 2.14, Ec = 1.77) and ‘Cedric Nuytinck’ (Ep = 2.02, Ec = 1.89).

Examining Ec/Ep is also a easier way to understand the tendency of elasticity of blades. Fig.07 shows the relationship between Ec/Ep and Ep.

Harimoto 07 G02
Fig.07 Ec/Ep vs. Ep

Ec/Ep expresses the ‘tendency’ of the elasticity of blade. By examining Ec/Ep and Ep at the same time, we can easily understand the behavior of blades.

On the graph, all the blades in this comparison except for reference blade are in the range of Ec/Ep < 1.0, i.e. ‘Hold’ range. ‘Harimoto ALC’ is in ‘Deep Hold’ range. ‘InnerForce Layer ALC’ is also in ‘Deep Hold’ range. But, the position of ‘InnerForce Layer ALC’ can be also be regarded as the the border between ‘Mild Hold’ range and ‘Deep Hold’ range. Anyway, the difference between Ec/Ep of ‘Harimoto ALC’ and that of ‘InnerForce Layer ALC’ is not significant. But, there is noticeable difference between Ep of ‘Harimoto ALC’ and that of ‘InnerForce Layer ALC’. Therefore we can conclude that ‘Harimoto ALC’ is more elastic variation of ‘InnerForce Layer ALC’.

Also, we can notice from the graph that ‘Harimoto ALC’ is close to ‘Timo Boll ALC’. Ep of ‘Harimoto ALC’ is not meaningfully different from that of ‘Timo Boll ALC’. The difference between ‘Harimoto ALC’ and ‘Timo Boll ALC’ is that the ‘Deep Hold’ characteristic of ‘Harimoto ALC’ is not as extreme as that of ‘Timo Boll ALC’. This will be the criterion when player wants to select between ‘Harimoto ALC’ and ‘Timo Boll ALC’. And, if the player needs a blade whose Ec/Ep is even milder while its Ep is close to that of ‘Timo Boll ALC’ or ‘Harimoto ALC’, the solution will be ‘Cedric Nuytinck’ which is placed in ‘Mild Hold’ range.


Then successively, let’s compare Vibration Indices. Fig. 08 shows the comparison graph of Vibration Indices.

Harimoto 08 G03
Fig.08 Comparison by Vibration Indices

Vibration Indices are concerned with feeling. Vp indicates primary feeling which is transferred to player’s palm. And, Vl is the feeling at the wing of a blade. It is felt by player’s index finger or middle finger.

The Vp of ‘Harimoto ALC’ is 1.24. It is noticeably higher than the Vp of ‘InnerForce Layer ALC’ (= 1.15). That is what we can expect from thicker construction of ‘Harimoto ALC’. The players who are sensitive to the primary feeling that is transferred through handle will feel that ‘Harimoto ALC’ is harder than ‘InnerForce Layer ALC’.

On the contrary, the Vl of ‘Harimoto ALC’ (= 1.20) is lower than that of ‘InnerForce Layer ALC’ (= 1.23). Because there isn’t much difference between the Lateral Vibration Indices of those two blades, the players who are especially sensitive to the feeling that is transferred through the side edges of blade may feel that ‘Harimoto ALC’ is not much different from ‘InnerForce Layer ALC’.

Interestingly, Vibration Indices of ‘Harimoto ALC’ (Vp = 1.24, Vl = 1.20) are very similar to those of ‘InnerForce Layer ZLC’ (Vp = 1.24, Vl = 1.21). Some players may feel that ‘Harimoto ALC’ is close to ‘InnerForce Layer ZLC’.

If we focus on shape of graph, we can notice that the blades (except for reference blade) in this comparison can be categorized into two groups – (1) ‘Vp > Vl’ group and (2) ‘Vp < Vl’ group.

Group A  (‘Vp > Vl’) : ‘Harimoto ALC’, ‘InnerForce Layer ZLC’, ‘Cedric Nuytinck’

Group B (Vp < Vl’) : ‘InnerForce Layer ALC’, ‘Timo Boll ALC’, ‘Korbel’

That is the difference of ‘tendency’ of feeling. Examining Vl/Vp is easier way for the comparison of the tendency of feeling. Vp/Vl of Group A blades is under 1.0. And, Vp/Vl of Group B blades is over 1.0.

Fig.09 shows the relationship between Vl/Vp and Vp for easier comparison.

Harimoto 09 G04
Fig.09 Vl/Vp vs. Vp

On the graph of Vl/Vp vs. Vp, Group A blades are placed at the area under the ‘Vl/Vp = 1.0’ line. And, Group B blades are placed at the area over that line. As always, we call the lower and upper areas ‘Relatively More Comfortable at Finger’ range and ‘Relatively Sharper at Finger’ range respectively. ‘Harimoto ALC’ is in the ‘Relatively More Comfortable at Finger’. But, the Vl/Vp of ‘Harimoto ALC’ is close to 1.0. Differently speaking, we can think that the feeling of ‘Harimoto ALC’ is quite uniform. On the contrary, ‘InnerForce Layer ALC’ is in the ‘Relatively Sharper at Finger’ range. Because the Vl/Vp of ‘InnerForce Layer ALC’ is under 1.10, it can also be regarded as ‘uniform’ blade. However, the distance between ‘InnerForce Layer ALC’ and ‘Vl/Vp = 1.0’ line is relatively bigger than the distance between ‘Harimoto ALC’ and ‘Vl/Vp = 1.0’ line. We will be able to call both of those two blades ‘near uniform’ (0.9 < Vl/Vp < 1.1) ones. The players who are not sensitive may feel that those to blades give nearly identical feeling. But, sensitive players will be able to distinguish those blades just by the difference of feeling.

‘InnerForce Layer ZLC’ is placed very close to ‘Harimoto ALC’ although it has different material from ‘Harimoto ALC’. Also, ‘Cedric Nuytinck is quite close to ‘Harimoto ALC’ although it is not an inner-fiber blade.

‘Korbel’ and ‘Timo Boll ALC’ are placed at ‘Relatively sharper at finger’ range. But, those two can’t be regarded as ‘near uniform’ ones. In case a player wants to replace Korbel with faster one while keeping feeling, ‘Timo Boll ALC’ may be better solution than ‘InnerForce Layer ALC’.


Harimoto 10


4. Summary

The result of comparison can be summarized as follows :

  • ‘Harimoto ALC’ (= ‘Harimoto Tomokazu InnerForce ALC’) is noticeably faster (= more elastic) than ‘InnerForce Layer ALC’. ‘InnerForce Layer ALC’ is just a bit faster than ‘Korbel’. However, ‘Harimoto ALC’ is as fast as ‘Timo Boll ALC’. Both of those hold ball very well when player hits the ball very strongly.
  • ‘Harimoto ALC’ is harder than ‘InnerForce Layer ALC’. However, the feeling of ‘Harimoto ALC’ that is felt at the fingertip of index finger is not meaningfully different from that feeling of ‘InnerForce ALC’. Some players will easily distinguish one from the other. However, the other players will feel that those two blades are similar to each other.

‘Harimoto ALC’ is based on ‘InnerForce Layer ALC’. However, as we can expect from thicker construction and heavier weight, ‘Harimoto ALC’ is different from ‘InnerForce Layer ALC’. Some aspects (The Ep around 2.0 and the Vl/Vp which is close to 1.0) of ‘Harimoto ALC’ remind us of some classic 7-ply wood blades such as ‘Clipper’ series, while ‘InnerForce Layer ALC’ is relatively closer to ‘Korbel’ which is the representative of classic offensive 5-ply wood blade. The difference between ‘Harimoto ALC’ and ‘InnerForce Layer ALC’ is similar to the difference between ‘Clipper Wood’ and ‘Korbel’. This result may be good guideline when you choose between ‘Harimoto ALC’ and ‘InnerForce Layer ALC’. If you want to select a blade which isn’t slower than ‘Timo Boll ALC’ but whose feeling is much more natural than ‘Timo Boll ALC’, ‘Harimoto ALC’ will be a good solution. But, if you like the overall characteristics of ‘InnerForce Layer ALC’ including moderate elasticity, please don’t select ‘Harimoto ALC’ just because of its special design. ‘Harimoto ALC’ can be  the replacement of ‘InnerForce Layer ALC’ only when the player needs higher speed and heavier weight.

Harimoto 11


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