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Specialist Cricket Retailers => VKS => Topic started by: Kal on January 20, 2015, 05:17:51 PM

Title: Interesting video on concaving
Post by: Kal on January 20, 2015, 05:17:51 PM
Just seen this.

http://m.youtube.com/watch?v=tuKKGQf2Afg&list=UU2Elu5HROyIZ0JXs4h6TfLw&params=OAFIAVgF (http://m.youtube.com/watch?v=tuKKGQf2Afg&list=UU2Elu5HROyIZ0JXs4h6TfLw&params=OAFIAVgF)

Good to see one of the big bat manufacturers on video.

Thinking the bit around 2mins 30 might surprise a few people...
Title: Re: Interesting video on concaving
Post by: procricket on January 20, 2015, 05:40:29 PM
Great Video it is hard to get a massive bat with big edges under 2-10 plain and simple.

Brilliant video up my street that
Title: Re: Interesting video on concaving
Post by: WalkingWicket37 on January 20, 2015, 05:43:09 PM
Great Video it is hard to get a massive bat with big edges under 2-10 plain and simple.

Brilliant video up my street that

You manage to get hold of your fair share of them Dave  ;)
Title: Re: Interesting video on concaving
Post by: Vitas Cricket on January 20, 2015, 05:59:10 PM
Just seen this.

[url]http://m.youtube.com/watch?v=tuKKGQf2Afg&list=UU2Elu5HROyIZ0JXs4h6TfLw&params=OAFIAVgF[/url] ([url]http://m.youtube.com/watch?v=tuKKGQf2Afg&list=UU2Elu5HROyIZ0JXs4h6TfLw&params=OAFIAVgF[/url])

Good to see one of the big bat manufacturers on video.

Thinking the bit around 2mins 30 might surprise a few people...


In my opinion, the most important factor in the performance of a bat is the pressing. The quality of the piece of willow will also have an obvious impact. You can be a dab hand at pressing but a dud cleft will make a dud bat.

Removing wood from various areas of the back of the bat affects balance and pick up more than anything. In my opinion concaving has little impact on performance, if any.

If removing wood from the back of the bat made such a difference then the GN scoop would be the worst bat ever made.

I have owned concaved and non concaved bats, some of my favourites including the best performing bat I've ever owned have been concaved.


:)
Title: Re: Interesting video on concaving
Post by: procricket on January 20, 2015, 06:03:38 PM
Also a easier way of selling heavier clefts whilst still looking big!!!

More volume of wood gives you more power. :D


Title: Re: Interesting video on concaving
Post by: praguetaz on January 20, 2015, 06:19:23 PM
Great video which has revived my faith in a little bit of concaving and most likely renewed my confidence in some lovely bats that I have. I'm not as lucky as some to have 2.8-9 bats but with the amount of time I'm likely to be at the wicket - 2.10-11 bats should be fine.

I realise that if I was a big hitter then a fuller profile is more ideal for clearing the boundary but not at the cost of being able to play a range of shots all around with timing. I really think for me focusing on timing is the best way to reach boundaries more consistently as well as a well pressed bat. If the concaving keeps rigidity in the willow to stop it twisting in the hands then that's good enough for me.

Thanks again Kal....
Title: Re: Interesting video on concaving
Post by: wayward_hayward on January 20, 2015, 06:51:50 PM
Fantastic video and a great insight into the view of a bat maker.
Title: Re: Interesting video on concaving
Post by: Mattsky on January 20, 2015, 07:28:49 PM
Good video, thanks for posting Kal. Food for thought. Hadn't occurred to me that the concaving acts as an archway to give structural rigidity to the blade. Got the Romans to thank for that. Thought it was all about weight reduction and big edges. However, still believe that if you can get it, you can't beat a full profile shape in a light density willow.
Title: Re: Interesting video on concaving
Post by: procricket on January 20, 2015, 07:29:45 PM
Good video, thanks for posting Kal. Food for thought. Hadn't occurred to me that the concaving acts as an archway to give structural rigidity to the blade. Got the Romans to thank for that. Thought it was all about weight reduction and big edges. However, still believe that if you can get it, you can't beat a full profile shape in a light density willow.

100 per cent mate :D
Title: Re: Interesting video on concaving
Post by: Buzz on January 20, 2015, 07:43:10 PM
good to see Chris King getting some publicity.

really interesting video, thanks for posting and thanks to VKS for recording the question and answer, certainly not the answer I was expecting.

Title: Re: Interesting video on concaving
Post by: edge on January 20, 2015, 08:20:41 PM
Interesting video, and agreed that concaving can still produce excellent bats. However, not buying the arch rigidity idea for even half of one second, that just isn't how arches work at all.
Title: Re: Interesting video on concaving
Post by: Beachcricket on January 20, 2015, 08:48:11 PM
I do agree that the shape can impact rigidity but not in the same way. I've asked to see the study and will be chasing this with Imperial College London.

However, the validity of this idea of "rigidity in twisting" is greatly dependent upon the method the Imperial College London used to test the twisting. If it's what I think, then I fear they've provided GN with useless data.

It's important when explanations like this are offered, especially with reference to scientific research, that the evidence is provided for scrutiny. Otherwise we get a "BIG BAT = POWERFUL BAT" myth being propagated.

I mean no offence to GN or Chris, I have nothing but respect for them.


EDIT: I would like to say, I enjoy it when bat makers come up with theories. It shows they're thinking and opens up debate on a craft I love.
Title: Re: Interesting video on concaving
Post by: edge on January 20, 2015, 09:25:15 PM
Here it is, twisting measurements are actually discussed with regards to moment of inertia rather than structural rigidity. Assuming they haven't performed any extra work that's not referenced in this report, there's no structural analysis of the bat at all, just energy absorption and MOI calculations. Slightly disappointing as it's good to hear from a batmaker in this way, but the GN chap appears to have been a little misleading when talking about this study.
http://www.lords.org/assets/Agenda-item-11.3-size-of-cricket-bats.pdf (http://www.lords.org/assets/Agenda-item-11.3-size-of-cricket-bats.pdf)
Title: Re: Interesting video on concaving
Post by: Kal on January 20, 2015, 09:33:51 PM
Good video, thanks for posting Kal. Food for thought. Hadn't occurred to me that the concaving acts as an archway to give structural rigidity to the blade. Got the Romans to thank for that. Thought it was all about weight reduction and big edges. However, still believe that if you can get it, you can't beat a full profile shape in a light density willow.

Not a problem, glad I didn't waste people's time.

Having watched the video again a few points struck me.

Was interesting that Chris referred to the scoop as having the the most rigidity. I always wanted a scoop but i can't get my head around the fact there is a lot of wood missing from the strike zone....

Also like the fact that Chris implied that trends /fashions seem to dictate how bats are being made. Ie it's the fashion for a fuller non concaved bats now. What do people think will be the next trend/fashion?

Like the Luke wright example, i.e. wanting a big bat but had to accept a heavier bat. Would love to see the finished bat though. I imagine it would be a monster.

On another note good to see the Vks boys posting some interesting videos. More please...

Title: Re: Interesting video on concaving
Post by: Bambooman on January 20, 2015, 10:03:12 PM
Here it is, twisting measurements are actually discussed with regards to moment of inertia rather than structural rigidity. Assuming they haven't performed any extra work that's not referenced in this report, there's no structural analysis of the bat at all, just energy absorption and MOI calculations. Slightly disappointing as it's good to hear from a batmaker in this way, but the GN chap appears to have been a little misleading when talking about this study.
[url]http://www.lords.org/assets/Agenda-item-11.3-size-of-cricket-bats.pdf[/url] ([url]http://www.lords.org/assets/Agenda-item-11.3-size-of-cricket-bats.pdf[/url])


Interesting to note that only one of the bats in this study is actually legal in terms of width!
Title: Re: Interesting video on concaving
Post by: Beachcricket on January 20, 2015, 10:20:25 PM
Interesting to note that only one of the bats in this study is actually legal in terms of width!

Perhaps the scuff sheet taking them over the limit?

I'm sure Chris and GN acknowledge this as a theory only since it's very difficult to account for the natural variation in timber. Designing a solid study accommodating these variables that isn't open to criticism is almost impossible. The subjectivity and beauty of bat making.
Title: Re: Interesting video on concaving
Post by: Bambooman on January 20, 2015, 10:25:02 PM
Perhaps the scuff sheet taking them over the limit.

I would be surprised if any of the bats used had scuff sheets on for the purposes of the test. Also the 1902 model would unlikely have one surely?
Another case for the bat police:)
Title: Re: Interesting video on concaving
Post by: Beachcricket on January 20, 2015, 10:33:01 PM
I would be surprised if any of the bats used had scuff sheets on for the purposes of the test. Also the 1902 model would unlikely have one surely?
Another case for the bat police:)

Perhaps some generous rounding up on the measurements then.
Title: Re: Interesting video on concaving
Post by: edge on January 20, 2015, 11:42:38 PM
I'm sure Chris and GN acknowledge this as a theory only since it's very difficult to account for the natural variation in timber. Designing a solid study accommodating these variables that isn't open to criticism is almost impossible. The subjectivity and beauty of bat making.
Wouldn't be too hard to make a comparison between the rigidity of different bat shapes only however, which I think would be more interesting from a scientific point of view. Conclusions from something like that could then be applied by a skilled batmaker in the more subjective craft of bat making.
Title: Re: Interesting video on concaving
Post by: Mattsky on January 21, 2015, 08:50:33 AM
Returning to the idea of concaving providing structural rigidity - this may well be true (or not) but thinking about it, isn't the primary function of an arch to disperse the weight of a load? Specifically, down through its support columns. Is this what we mean by structural rigidity? So does the concave-shaped arch spread the impact of a ball across the face to help offset twisting? Seems a bit of a stretch.
Title: Re: Interesting video on concaving
Post by: Stuey on January 21, 2015, 09:14:08 AM
Returning to the idea of concaving providing structural rigidity - this may well be true (or not) but thinking about it, isn't the primary function of an arch to disperse the weight of a load? Specifically, down through its support columns. Is this what we mean by structural rigidity? So does the concave-shaped arch spread the impact of a ball across the face to help offset twisting? Seems a bit of a stretch.
I dont buy this either, I understand an arch forming rigidity and strength under load, its why you should always lift with an arched back, but prevent twisting sounds like a selling gimmick. Wouldn't it need some form of anchorage at the bottom of the bat to support both ends. Just my layman thinking, but i would think an arched bridge would still twist if not anchored at both ends.
Title: Re: Interesting video on concaving
Post by: VKS on January 21, 2015, 09:31:20 AM
Great to see the video has been well received and shown the positive aspects of concaved bats.

We will be looking to create more videos like this and hopefully shed some more light on the art of bat making and do away with many myths.
Title: Re: Interesting video on concaving
Post by: GarrettJ on January 21, 2015, 09:41:23 AM
best bat i've ever had or ever used was concaved a lot and had a 20mm edge.
Title: Re: Interesting video on concaving
Post by: VKS on January 21, 2015, 09:45:56 AM
best bat i've ever had or ever used was concaved a lot and had a 20mm edge.
Same here. I currently use a 2.6 SS Ton Gladiator that has an extreme amount of concaving and goes like an absolute dream.

What matters is to use a bat that feels right and forget all the obsession with using rulers and measuring edges and spine height.
Title: Re: Interesting video on concaving
Post by: Stuey on January 21, 2015, 09:49:09 AM
I'm a firm believer that its the skill of the batmaker not a specific template that makes a good bat. Chris eluded to this in the video.
Title: Re: Interesting video on concaving
Post by: VKS on January 21, 2015, 10:04:15 AM
I'm a firm believer that its the skill of the batmaker not a specific template that makes a good bat. Chris eluded to this in the video.
You are absolutely correct and another thing Chris mentioned when I was talking to him, was that a good maker will have the skills to make a bat feel lighter than its dead weight.
Title: Re: Interesting video on concaving
Post by: procricket on January 21, 2015, 10:31:54 AM
Just had a look at your videos mate got to say i like your style no crap and informative and using your experiance which lets be fair is quite extensive to give the customer proper feedback not just the sales pitch.

I'm looking forward to coming down to London soon i will deffinatly come in and bite your ear off.
Title: Re: Interesting video on concaving
Post by: Beachcricket on January 21, 2015, 10:33:40 AM
Wouldn't be too hard to make a comparison between the rigidity of different bat shapes only however, which I think would be more interesting from a scientific point of view. Conclusions from something like that could then be applied by a skilled batmaker in the more subjective craft of bat making.

You could, but you couldn't be sure that the Increase/Decrease in rigidity was as a result of the change in shape or due to natural variation in the Timber/Handle. Repeat measures would I suspect only muddy the water further and provide significant variation in rigidity between bats of the same shape. I think you hit the nail on the head with subjectivity, acknowledging that exists is the best route to objectivity.
Title: Re: Interesting video on concaving
Post by: VKS on January 21, 2015, 11:58:20 AM
Just had a look at your videos mate got to say i like your style no crap and informative and using your experiance which lets be fair is quite extensive to give the customer proper feedback not just the sales pitch.

I'm looking forward to coming down to London soon i will deffinatly come in and bite your ear off.
Thanks for your kind words :).  Cricket and bats especially are a passion.
Yes would be good to meet you too.
Title: Re: Interesting video on concaving
Post by: Bambooman on January 21, 2015, 12:25:59 PM
You could, but you couldn't be sure that the Increase/Decrease in rigidity was as a result of the change in shape or due to natural variation in the Timber/Handle. Repeat measures would I suspect only muddy the water further and provide significant variation in rigidity between bats of the same shape. I think you hit the nail on the head with subjectivity, acknowledging that exists is the best route to objectivity.

The most logical way to eliminate the variation of willow stiffness would be to produce the bat shapes in an homogenous material. that way you can directly correlate spacial dimensions to stiffness. That can then be modelled in the computer.
Title: Re: Interesting video on concaving
Post by: procricket on January 21, 2015, 12:36:49 PM
The most logical way to eliminate the variation of willow stiffness would be to produce the bat shapes in an homogenous material. that way you can directly correlate spacial dimensions to stiffness. That can then be modelled in the computer.

Already done mate...

Streaky through Loughborough did many a test way over my head but i'm sure he will share.

It all starts with just a pressed handled cleft oh the stiffness.

Title: Re: Interesting video on concaving
Post by: Bambooman on January 21, 2015, 12:43:09 PM
Already done mate...

Streaky through Loughborough did many a test way over my head but i'm sure he will share.

It all starts with just a pressed handled cleft.

Interesting, played about with it a bit myself actually but couldn't really be construed as valid research.
Title: Re: Interesting video on concaving
Post by: Beachcricket on January 21, 2015, 01:07:00 PM
The most logical way to eliminate the variation of willow stiffness would be to produce the bat shapes in an homogenous material. that way you can directly correlate spacial dimensions to stiffness. That can then be modelled in the computer.

Willow isn't though, so you may find a correlation but as you know that doesn't imply causation. Anyone who's actually broken out some tools and worked Willow will know that no 2 clefts are the same.
Title: Re: Interesting video on concaving
Post by: Bambooman on January 21, 2015, 01:57:01 PM
Willow isn't though, so you may find a correlation but as you know that doesn't imply causation. Anyone who's actually broken out some tools and worked Willow will know that no 2 clefts are the same.

Yes but if you want to eliminate the variability of willow in order to focus specifically on geometric stiffness it's the only practical way. And quite a simple study to undertake provided you have the software
Title: Re: Interesting video on concaving
Post by: Beachcricket on January 21, 2015, 02:39:42 PM
How would you then compare the results of a homogenous material to Willow? Or are you saying that it would be useful as information for further theory?
Title: Re: Interesting video on concaving
Post by: tushar sehgal on January 21, 2015, 03:00:44 PM
Here is an idea, forget science  :D

Get a few bats of similar weight, middle position etc have one concaved, one not concaved and one with a high spine (like Vantage Emerald or H4L tempo) then set the bowling to enable you to play drives (cover or on drives) and see what happens....nets for a cause :)..see if you feel more twisting in one kind of shape or not...
Title: Re: Interesting video on concaving
Post by: Bambooman on January 21, 2015, 03:01:55 PM
How would you then compare the results of a homogenous material to Willow? Or are you saying that it would be useful as information for further theory?

Without going back and reading the thread. I thought the question was to examine the relationship between geometry and blade stiffness or have I got lost?
Title: Re: Interesting video on concaving
Post by: Beachcricket on January 21, 2015, 03:13:22 PM
Without going back and reading the thread. I thought the question was to examine the relationship between geometry and blade stiffness or have I got lost?

I don't know now you've said that. I think the point I was making was that theories are great but they require evidence to support them if they're going to be used to sell a product. However the nature of the material used dictates that testing Willow objectively could be tricky. I don't like it when theory is quoted as fact, I do it myself sometimes and have to correct what I say. You should see some of the draft articles I've written, they're full of edits and disclaimers.

Always fun discussing these ideas though.
Title: Re: Interesting video on concaving
Post by: Bambooman on January 21, 2015, 03:21:07 PM
I don't know now you've said that. I think the point I was making was that theories are great but they require evidence to support them if they're going to be used to sell a product. However the nature of the material used dictates that testing Willow objectively could be tricky. I don't like it when theory is quoted as fact, I do it myself sometimes and have to correct what I say. You should some of the draft articles I've written, they're full of edits and disclaimers.

Always fun discussing these ideas though.

I think as we both know there are many myths floating around the art bat making, part of why it's an art to begin with of course. I also think many myths are used to some individuals advantage in marketing. There may therefore be a general unwillingness to bust them.
Title: Re: Interesting video on concaving
Post by: edge on January 21, 2015, 06:39:39 PM
Without going back and reading the thread. I thought the question was to examine the relationship between geometry and blade stiffness or have I got lost?
This is what I was getting at, would be very easy to do on the computer to identify the best theoretical shape to use, and the batmaker's skill then comes into play when trying to achieve close to that using different clefts of willow.

@procricket B3 - I was actually thinking Streaky must have done something along these lines! Would be very interesting to hear about his reasearch if he's willing to share a little.
Title: Re: Interesting video on concaving
Post by: Bambooman on January 21, 2015, 08:38:20 PM
This is what I was getting at, would be very easy to do on the computer to identify the best theoretical shape to use, and the batmaker's skill then comes into play when trying to achieve close to that using different clefts of willow.

@procricket B3 - I was actually thinking Streaky must have done something along these lines! Would be very interesting to hear about his reasearch if he's willing to share a little.
I would be very surprised if B3 were willing to share their intellectual property. Very few bat makers have CAD models of the bats they produce and I think it unlikely the entire forum would be willing to sign an NDA :)
Title: Re: Interesting video on concaving
Post by: procricket on January 21, 2015, 08:39:53 PM
I would be very surprised if B3 were willing to share their intellectual property. Very few bat makers have CAD models of the bats they produce and I think it unlikely the entire forum would be willing to sign an NDA :)

Streaky will chat about his findings when he has time i have made him aware .
Title: Re: Interesting video on concaving
Post by: Bambooman on January 21, 2015, 08:47:02 PM
Streaky will chat about his findings when he has time i have made him aware .
Fair play to you!
Title: Re: Interesting video on concaving
Post by: The Doctor on January 21, 2015, 10:26:26 PM
Very interesting topic thus far and love the fact that people are talking and discussing bat shapes and how it affects the bats performance.

For me it is quite simple and Chris did mention it a few times in the video, only reason to concave is to reduce weight whilst still maintaining a visually big bat. There is absolutely no evidence; especially in the paper that he refers too that concaving increases the structural integrity. The reference to a bridge did make me laugh a little. Bridges and Bats, the only thing that they have in common is the B.... One is a static load whilst the other is a dynamic impact. I'm afraid the majority of the video is marketing and marketing alone, which is done quite a lot by the big boys.......


I think all the comments have merit in this thread- the first is about shape and optimising that shape to get the maximum performance and the other is about the willow, and maximising the material to get maximum performance.

What I would do is this;

Calculate the optimum bat shape with a homogenous material - that will take the natural variation in material out of the equation and we could say that design A is superior  (CoR) to design B for a given impact position, given a uniform weight and swing speed.

 The next question I would ask is that what makes design A superior, and would design A still be superior to B, if the ball impacted in a different position. I think the answer to that would be no, and therefore there is no optimum bat shape, and each player (both amateur and Professional) would have an optimum bat shape. This is where the 1271 shape comes into its own as it has a very large middle, and excellent CoR all the way up the blade. However this is not the Eureka bat shape as it would be too heavy using the average density for the majority of cricket players. Therefore you would need to calculate each person’s optimum bat design to get the most out of the cleft and have the facility to manufacture bespoke bats…….. .

The second aspect is the material used and is cleft A better than cleft B. There are visual indicators which can indicate whether a cleft A will play better than cleft B, but as willow is natural you will always get a natural variation irrespective of these indicators. Again, this is where the skill of the bat maker comes into play to make sure that they optimise the performance of each cleft, making an average cleft good, a good cleft great and a great cleft phenomenal – this is all done in the pressing.

Streaky