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Online now: 1 member: scottflodin; 15 anonymousDiscussion: Finding a bat's swing weight
| Posted | Discussion |
| Jan. 8 BruceinGa Men's 70 3233 posts | Has anyone else found themselves scratching their head after reading Bash Bro's article in the latest SSUSA News? For those that haven't seen it, check out page 4. He states that you should use two scales, one under the balance point of a bat and the other.....well, I'm confused. The method that I use(per my buddy in Tacoma), is to put the knob on a fixed support and the barrel on the scale. This will give the swing weight. Turn the bat around with the knob on the scale and this number added to the swing weight it the total weight. Or, if looking for total weight just weight the bat standing on the endcap. I do applaud Bash for trying to describe this to us. Swing weight is important. |
| Jan. 8 Fred S Men's 85 297 posts | Why get so complicated. Wouldn't getting the balance point tell you the same thing. Why do you need to know the weight. |
| Jan. 8 BruceinGa Men's 70 3233 posts | Fred, A balance point would indicate if one bat was more end loaded than another, just not how much more. I'm thinking two end loaded might have the same balance point but one could be an ounce or two more. I don't now this for a fact, just guessing. I don't rely much on balance points. |
| Jan. 8 16wood Men's 65 77 posts | Bruce, I have never really cared about its swing weight as much as its balance point. To determine how end loaded one bat is when compared to another... I put them side by side on a flat horizontal surface (that is 3' wide or more)... with the knob placed closest to the table edge, I gradually move both toward the edge. The one that hangs on longer is more end loaded. Putting 3 or more bats in this position can provide a broader comparison. I recently did this with new Miken Max Loads, one is a 26 oz demo and the other was a 27 oz production model. Both have a 1/2 oz load in the end, therefore, I expected them to react exactly alike to this test. They didn't... we finally figured this out... because the end load is a precise, defined amount (1/2 oz) the balance point will be different for the same model but different weights. Of course, comparing a Big Cat to a Max Load produces different results as well. But while this comparison works for me, others may well want to know the actual swing weight. You are probably more learned on this than most players. I read the article in the SSUSA newspaper as well. That methodology won't work for me either. BW |
| Jan. 8 fennellwg Men's 60 97 posts | gentlemen, knowing any of the following is essentially the same thing: -the location of the balance point -the weight of each end of the bat -the weight of one end and the total weight Ideally this info would be used to determine moment of inertia of the bat. regardless of weight, end-load, balance point etc. you should be able to swing bats of equal MOI at the same speed. not quite the final word in determining the batted ball speed, but a good step in the right direction. IMO -bill |
| Jan. 8 Fred S Men's 85 297 posts | As the location of the balance point changes the weight on each end is going to change also. I have two 29.4 oz bats and the balance point is different on each so I know the one with the bigger balance point is going to swing heavier than the other so why do I care what the actual weight is of each end? It looks like taking a simple answer and making it more complicated with the end results the exact same. |
| Jan. 8 BruceinGa Men's 70 3233 posts | Fred, if you were thinking of buying another bat you could find the swing weight of it and compare the weight to yours. Much better than picking one up and wiggling it and thinking "this feels right". You really don't care what the swing weight is, since it probably isn't accurate from one setup to another. You should just compare the ones that you have measured. |
| Jan. 8 CallaVett Men's 50 61 posts | Bruce I have also used the method you described but my source was the same as yours. I know your buddy in Tacoma and Bash BP together a lot. So, I didn't understand it either. Steve |
| Jan. 9 fennellwg Men's 60 97 posts | Bruce, To answer your first question. I think I've seen the setup you are asking about. If the bat barrel is resting on the balance point , the scale shoul read the bats total weight. The other scale should read zero as confirmation. If the support for the "zero" scale is located 6" from the knob, The distance between the 2 supports is used the compute the MOI of the bat. A bit over complicated, but just allows all the numbers to go straight into the equation for moi w/o any adjustments. Im sure balancing the bat on your finger is pretty much the same thing. I hope that helps. Bill |
| Jan. 9 Fred S Men's 85 297 posts | Bruce: When I buy a bat I usually ask the actual weight of the bat. For example if I am buying a 28 oz bat and the actual weight is 28.8 oz then I am pretty sure that the swing weight/balance point is just right for me. I just bought a 28 oz Worth Ligit HD52 and the reason I bought that one is it weighed 28.8 oz which turned out to be just right for me. A good end load feel without being too heavy. Reminds me of all my PST's that I owned. |
| Jan. 9 DieselDan Men's 75 602 posts | It's been suggested before to take 2/3 bats of the same weight, lay them on the counter with the barrel facing you and, slowly move them towards you. Mark where they start to fall forward. The one that falls first has more end load. |
| Jan. 9 Fred S Men's 85 297 posts | Forgot to mention I talking about weights of end loaded bats. |
| Jan. 10 obagain Men's 50 72 posts | The reason you want to know swing weight is it is a true number, balance point isn't. If I find the balance point of a bat where the barrel is made of heavy material like Kevlar it will balance as an end load even though most of that end load is likely from 6" from the end of the bat to the endcap. If they used a lighter material you would have to add more weight to the cap to get the same overall weight. The lighter barrel is a heavier swing weight but the same balance point. I put the cap end of the bat on the scale and rest the knob so that the barrel is slightly off the scale, only the edge of the bat is on the scale. |
| Jan. 21 fennellwg Men's 60 97 posts | Bruce, all I'm sure most of you have let this go, even if you don’t already have your own process to evaluate bats. I did find a thread which references the ASTM spec used to measure bats prior to acceptance testing by ASA or NCAA or even SSUSA. (ASTM Standard F2398-04 Test Method for Measuring Moment of Inertia and Center of Percussion of a Baseball of Softball Bat) Descriptive link: http://www.acs.psu.edu/drussell/bats/bat-moi-details.html This is the recipe that was being described in the forum news article that Bruce mentioned, but the recipe has a better description than the one provided by Bash Bro. The reason for the additional complexity is they want to know more than just the swing weight or balance point. Players our age generally have enough "feel" to compare bats if they are able to hold and swing them, Most use numbers like weight, balance point, swing weight, etc. to quantify the difference between bats. Although the above terms are relatively simple to understand, their relevance to bat speed or BPF or batted ball speed is incomplete and potentially misleading. The grownups at ASA believe that a bat's Moment of Inertia (MOI) is the key variable when comparing your bat speed for various designs. MOI is also the key variable ASA uses to track the bat-ball collision efficiency (BBCOR) (and BPF) when doing acceptance tests for a manufacturer's bat model. None of this is intended to make you believe that what you feel is incorrect. Its just that the number you should be using to describe it is the Moment of Inertia. MOI does combine both weight and balance point (along with a few other numbers) into a single variable that quantifies the bats resistance to rotation (what you feel when you try to swing it) Alan (Tri18) has been great in providing weight and balance measurements for bats I would like to compare but have no opportunity to swing. The estimated moment of inertia for a couple of Dudley end-loaded bats will allow me to compare swing speeds to bats I already own, in particular a Dudley 27 balanced. I've also pilfered the quoted swing weight of a Dudley EL12 that Bruce provided to compare its MOI with the 13 inch end-loads I have data for. If folks are interested in the estimated MOI for the few Dudley's that Alan and I have measured, I would be happy to post the results. If anyone is willing to provide weights and balance points for other bat flavors, I would add those MOI estimates to the list as well. So far the best part of this list is that comparisons made are still compatible with the great advice Alan has provided for selecting a bat. If you're shopping, MOI will give you confidence that the bat will swing the same as your favorite. Whether or not it's as hot as advertised....you'll have to ask Alan or try it out for yourself. -bill |
| Jan. 21 BruceinGa Men's 70 3233 posts | Thanks Bill, for the addendum. I am skeptical that you can use my figures and come up with a meaningful result unless you and I have compared each other's setup. I've found that even 1/4" can distort the outcome. I've made a jig to each bat that I weigh will be positioned identically. Thanks again for your time taken in presenting this. |
| Jan. 21 fennellwg Men's 60 97 posts | Yeah, No argument from me. The math doesn't, really care which technique you use. But errors will create more variability in either case. That's probably the reason for the jig you see in the ASTM procedure. I suspect it has a bit more precision and repeatability when compared to either method that we use. What interested me most about your particular results was that you weighed a 27 EL12 and 28 EL12 with similar swing weights. I was curious to see which number did not follow the trend. |
| Jan. 21 BruceinGa Men's 70 3233 posts | I have a 29oz also. When I get some time I will verify all. |
