80mm CoC #3 153rgc

[Kevin Gripz]

This one is wideeeeeee. My GHP10 262rgc is only 75.1mm and CoC #4 212rgc is only 72.9mm

[Kevin Gripz]

4 minutes ago, Kevin Gripz said:

This one is wideeeeeee. My GHP10 262rgc is only 75.1mm and CoC #4 212rgc is only 72.9mm

[Kevin Gripz]

7 minutes ago, Kevin Gripz said:

This one is wideeeeeee. My GHP10 262rgc is only 75.1mm and CoC #4 212rgc is only 72.9mm

pictures coming soon if it will let me post them

[C8Myotome]

35 minutes ago, Kevin Gripz said:

pictures coming soon if it will let me post them

I'll post your picture for you lol yeah this is an awesome gripper

[Kevin Gripz]

1 minute ago, C8Myotome said:

I'll post your picture for you lol yeah this is an awesome gripper

Haha thank you for posting!!!!

[Jared P]

That thing is awesome.

My two widest grippers are:

96 rgc Standard Gold - 79mm
234 rgc Robert Baraban 365 - 80mm

I absolutely love ultra-wide grippers.

[dubyagrip]

Let me borrow it. I want to TNS it.

[Kevin Gripz]

12 hours ago, Jared P said:

That thing is awesome.

My two widest grippers are:

96 rgc Standard Gold - 79mm
234 rgc Robert Baraban 365 - 80mm

I absolutely love ultra-wide grippers.

Those are 2 I wish I had Jared very cool

[EmilBB]

That #3 is super wide for it's RGC, my widest is this Standard Pt, also have one rated 118 at 80mm. 

Edited October 5, 2023 by EmilBB

[Vinnie]

Wondering if the extra width makes it harder to set to parallel, because more of the range has to be done with the set, but then easier to finish from parallel, because you've already accounted for a larger percentage of its resistance by setting it?  I don't know, just wondering.  I've always just considered my grippers' RGC ratings, and never measured them (although I am aware of which ones are especially narrow or wide just by feel).  

[EmilBB]

20 minutes ago, Vinnie said:

Wondering if the extra width makes it harder to set to parallel, because more of the range has to be done with the set, but then easier to finish from parallel, because you've already accounted for a larger percentage of its resistance by setting it?  I don't know, just wondering.  I've always just considered my grippers' RGC ratings, and never measured them (although I am aware of which ones are especially narrow or wide just by feel).  

The wide gripper is under more tension when it's set to parallel compared to a narrow gripper, at least that's what I have noticed and @C8Myotome has made a video about it which confirms it.

I trained grippers today and was supposed to do 3-5 GHP block reps, first set I used my Standard Pt rated 118 which has a 80mm spread (I got 3 reps). Next set I used my light #2.5 which I have rated at 124 but it only has a 69mm spread, even though I was more fatigued I still got 4 reps almost 5 on this. So wider grippers are just harder in every way, at least that's what I have noticed.

[C8Myotome]

1 hour ago, Vinnie said:

Wondering if the extra width makes it harder to set to parallel, because more of the range has to be done with the set, but then easier to finish from parallel, because you've already accounted for a larger percentage of its resistance by setting it?  I don't know, just wondering.  I've always just considered my grippers' RGC ratings, and never measured them (although I am aware of which ones are especially narrow or wide just by feel).  

Yes, if you think about RGC output as going from 0% at rest to 100% at full close, and different set widths as different % start-to-finish closed, you can get ideas of how heavy a gripper is at each point from the path of start to finish, or you can just use RGC and handle spread and calculate slope to get an idea of how heavy it is at set position etc..

Just to make an even easier example than what I've already explained in other occasions let's take 2 grippers both of 100 RGC but one is GHP, and one is heavy grips...the GHP has a 2 cm wider spread

So you want to compare how heavy each gripper is with a 38 mm GHP block set in it...the GHP must travel *half* its handle spread distance to reach this position to set on a GHP block so the GHP would put out half its total resistance by this point so it would be 50 RGC in the set position. 

A heavy grips is already so narrow that by the time you have set it onto a GHP block, the handles have barely changed position, let's say the gripper has only closed 25% of its total spread by the time both handles touch the GHP block - so this gripper would be putting out *25%& of its total RGC and only be as heavy as 25 RGC before you actually attempt your close

23 minutes ago, EmilBB said:

The wide gripper is under more tension when it's set to parallel compared to a narrow gripper, at least that's what I have noticed and @C8Myotome has made a video about it which confirms it.

I trained grippers today and was supposed to do 3-5 GHP block reps, first set I used my Standard Pt rated 118 which has a 80mm spread (I got 3 reps). Next set I used my light #2.5 which I have rated at 124 but it only has a 69mm spread, even though I was more fatigued I still got 4 reps almost 5 on this. So wider grippers are just harder in every way, at least that's what I have noticed.

Yup, even with a slightly "heavier" gripper, you may be actually putting out less force to combat how heavy it is with a GHP block in it, where you will overall be spending the most time while resetting the block for each rep. A slightly "lighter" via total RGC gripper would be putting out more force while you are holding the GHP block around it.

These differences matter...the amount of resistance in the set position is what you have to re-accelerate the handles from, and you get a higher resistance here the wider of a gripper you use, because the handles have travelled farther from their start position to reach set position

So if you only train narrow grippers you're just not spending any time with the gripper also being difficult in the set position

There are still people that will tell me none of this matters and that chinese grippers are awesome etc etc but the facts are facts

Who really cares who can close a heavy grips 250 if they can't even manage to hold a coc 2 in a set position much less close a coc 2, etc.

Narrow grippers are more similar to just holding a barbell at that point...there is less crush going on, and more just something only being heavy in a really small position

You have to actually crush wide grippers

Even from a parallel set, an equivalent GHP will be putting out a higher % of its resistance than a narrow gripper like heavy grips...you're not facing as much resistance in the set position

It's not exactly rocket surgery

The more narrow of grippers you use, the more you are doing akin to a rack pull than a deadlift. Similarly, no one would care how much you can rack pull it you can't move the same weight past your shins, much less budge it off the floor

Edited October 5, 2023 by C8Myotome

[Cannon]

This is actually a hard issue to capture. The rating is the rating in either case because that figure is simply "pounds at the close", but a wider gripper is more total work. So in Derek's example of two grippers that both rate 100, the narrow gripper doesn't feel easier because the pounds at close isn't actually 100, but rather it feels easier because it was less total work to get to closed which ratings do not capture well. This is an inherent shortcoming of the current ratings system. (In addition to things like that it cannot capture the added difficulty of smooth handles but that varies by person anyway. Some people lose almost nothing to smooth handles and others it cuts their performance in half.) 

It's the same thing Derek said, just wording it how it makes sense to me. Like I have two grippers here that both rate 177. An HG350 with a 56 mm spread and an IM 3.5 with a 71 mm spread. They have the same final number but stack up like this along the way:

• Open: Both zero pounds
• CCS: IM 38 lbs, HG still zero (because the spread is barely wider than CCS)
• 30 mm: IM 94, HG 74
• 20 mm: IM 116, HG 110 (getting closer)
• Closed: IM 177, HG 177

The interesting thing is that choked at 10 mm they would feel pretty similar because at that point the remaining work is almost identical. But in your hand, setting from open, you have to do all the work and wider grippers are simply more work. 

CPW is experimenting with ways to capture this. Like getting computers involved to plot total work, etc. There are lots of monkey wrenches though when you start trying to have a "feels like" output. For example, wide grippers are less of a problem for people with a strong set or if you're working below your max. So this all falls apart somewhat when you're talking about individual people. From 20 mm, the two grippers aren't that different. If your set sucks (like mine) you're really going to feel the work to set and hold at 20 mm. If you have a strong set and your max is 190 anyway, those two grippers will feel pretty similar from 20 mm. All of these "feels like" variables are honestly a really challenging and interesting problem.  

 

[EmilBB]

13 minutes ago, Cannon said:

This is actually a hard issue to capture. The rating is the rating in either case because that figure is simply "pounds at the close", but a wider gripper is more total work. So in Derek's example of two grippers that both rate 100, the narrow gripper doesn't feel easier because the pounds at close isn't actually 100, but rather it feels easier because it was less total work to get to closed which ratings do not capture well. This is an inherent shortcoming of the current ratings system. (In addition to things like that it cannot capture the added difficulty of smooth handles but that varies by person anyway. Some people lose almost nothing to smooth handles and others it cuts their performance in half.) 

It's the same thing Derek said, just wording it how it makes sense to me. Like I have two grippers here that both rate 177. An HG350 with a 56 mm spread and an IM 3.5 with a 71 mm spread. They have the same final number but stack up like this along the way:

• Open: Both zero pounds
• CCS: IM 38 lbs, HG still zero (because the spread is barely wider than CCS)
• 30 mm: IM 94, HG 74
• 20 mm: IM 116, HG 110 (getting closer)
• Closed: IM 177, HG 177

The interesting thing is that choked at 10 mm they would feel pretty similar because at that point the remaining work is almost identical. But in your hand, setting from open, you have to do all the work and wider grippers are simply more work. 

CPW is experimenting with ways to capture this. Like getting computers involved to plot total work, etc. There are lots of monkey wrenches though when you start trying to have a "feels like" output. For example, wide grippers are less of a problem for people with a strong set or if you're working below your max. So this all falls apart somewhat when you're talking about individual people. From 20 mm, the two grippers aren't that different. If your set sucks (like mine) you're really going to feel the work to set and hold at 20 mm. If you have a strong set and your max is 190 anyway, those two grippers will feel pretty similar from 20 mm. All of these "feels like" variables are honestly a really challenging and interesting problem.  

 

Nice to get some numbers on it, they're closer at 20mm than I expected.

[C8Myotome]

1 minute ago, Cannon said:

This is actually a hard issue to capture. The rating is the rating in either case because that figure is simply "pounds at the close", but a wider gripper is more total work. So in Derek's example of two grippers that both rate 100, the narrow gripper doesn't feel easier because the pounds at close isn't actually 100, but rather it feels easier because it was less total work to get to closed which ratings do not capture well. This is an inherent shortcoming of the current ratings system. (In addition to things like that it cannot capture the added difficulty of smooth handles but that varies by person anyway. Some people lose almost nothing to smooth handles and others it cuts their performance in half.) 

It's the same thing Derek said, just wording it how it makes sense to me. Like I have two grippers here that both rate 177. An HG350 with a 56 mm spread and an IM 3.5 with a 71 mm spread. They have the same final number but stack up like this along the way:

• Open: Both zero pounds
• CCS: IM 38 lbs, HG still zero (because the spread is barely wider than CCS)
• 30 mm: IM 94, HG 74
• 20 mm: IM 116, HG 110 (getting closer)
• Closed: IM 177, HG 177

The interesting thing is that choked at 10 mm they would feel pretty similar because at that point the remaining work is almost identical. But in your hand, setting from open, you have to do all the work and wider grippers are simply more work. 

CPW is experimenting with ways to capture this. Like getting computers involved to plot total work, etc. There are lots of monkey wrenches though when you start trying to have a "feels like" output. For example, wide grippers are less of a problem for people with a strong set or if you're working below your max. So this all falls apart somewhat when you're talking about individual people. From 20 mm, the two grippers aren't that different. If your set sucks (like mine) you're really going to feel the work to set and hold at 20 mm. If you have a strong set and your max is 190 anyway, those two grippers will feel pretty similar from 20 mm. All of these "feels like" variables are honestly a really challenging and interesting problem.  

 

It would be a ton more work but you could take like 10+ ratings for 1 gripper and plot them up x vs y to show what slope that gripper has, or you could just take the rough estimate method and provide the slope info alongside the RGC.

When we buy pre-rated grippers now, the only info we are going by is RGC. We have no idea what spread to expect, pretty much the only other factor like you aside (excluding smoothness) that affects overall difficulty.

So there's 3 types of data that determine gripper difficulty, and you only need the first 2 to find the 3rd.

1) RGC

2) Spread

3) Slope

I would like to compare this to motorcycles, where horsepower or max speed could be viewed as its maximum power output, but torque is a better figure to describe how "aggressive" the motorcycle, or gripper, is in its handling/performance. For example you could have 2 motorcycles with the same horsepower or top speed, but with completely different torque potentials, making one accelerate much faster than the other which accelerates slower.

So I think this could be possible without having to take any other data than what is currently being taken..it might make listing and selling pre-rated grippers more of a PITA to list handle spread and/or slope for every pre-rated gripper, but that's upto you how you want to handle that. Because you may have 20 different 152 CoC 3's in stock but all 20 of these have 8 different handle spreads total, so now you have 8 different pre-rated listings for a 152 CoC 3..

And this is something the buyer can just measure and calculate on their own anyways, but currently we have no way to pre-select wide grippers. 

I personally would rather buy a wider gripper in most circumstances, and at the moment just hope I get a wider one by chance.

So ideas for future gripper lingo of slope would be 

RGC/handle spread = slope

150 RGC / 55 mm = 2.72 RGC/mm slope

150 RGC / 75 mm = 2.00 RGC/mm slope

150 RGC / 82 mm = 1.82 RGC/mm slope

In this context the lower slope would mean a wider gripper with a longer spread for a harder set, and while it might not increase as much from set to close, it is much heavier in the set position where you have to re-accelerate it from

Just to use a different RGC how about

200 RGC / 55 mm = 3.63 RGC/mm

200 RGC / 75 mm = 2.66 RGC/mm

200 RGC / 82 mm = 2.43 RGC/mm

Again this is all stuff you can figure out once you own the gripper, we just have no idea what spread or slope we are getting when we order by RGC only...and some of would buy pre-rated extra wide grippers if we could select for those

[matek]

To illustrate the difference let's calculate Work. 
Work is a force causing an object to have a displacement. W = Fd. 
With RGC, we are measuring the force required to overcome the resistance of the spring. So F = RGC * g. 
The handles do not travel in a straight line, but it would make it unnecessarily complicated if we had to calculate the arc length for displacement. So we can just use the chord length -what we call "spread"- as a rough approximation. 

Of course, the problem is that we do not apply that much force from the very beginning. Without going into spring geometry and materials, let's assume that the increases linearly from 0 to the measure RGC value (as Derek did). 
The slope m would be (RGC * g)/spread, and F exerted when it's closed by a distance x is (RGC * g * x)/spread (same calculation Derek did, just including g). 
Work here is the integral of force with respect to displacement. Since we assume that force increases linearly with displacement, we just have a triangle under the curve (if we don't have the linear assumption -if we would take into consideration torsion spring constant for example-, we would have a "real" integral). The area of a right triangle: 1/2 x base x height, where in our case base is actually our displacement x, and the height is the force at the displacement. 
W = 1/2 * x * [(RGC * g * x)/spread], and if we simplify and just use the constant 9.81 as acceleration due to gravity (because we use grippers on Earth):
W = (RGC * 9.81 * x^2)/(2spread)

Let's calculate it for two hypothetical grippers (keep in mind that we need to use the correct units to get the work W in Joules):
RGC 150, 65mm spread, fully closed:
W = (68.04kg * 9.81m/s^2 * 0.00423m) / 0.13m = 21.72J
RGC 150, 80mm spread, fully closed:
W = (68.04kg * 9.81m/s^2 * 0.0064m) / 0.16m = 26.7J 
RGC 150, 65mm spread, set to 38mm block set:
W = (68.04kg * 9.81m/s^2 * 0.00073m) / 0.13m = 3.748J
RGC 150, 80mm spread, set to 38mm block set:
W = (68.04kg * 9.81m/s^2 * 0.00176m) / 0.16m = 7.342J
RGC 150, 65mm spread, set to 20mm block set:
W = (68.04kg * 9.81m/s^2 * 0.00203m) / 0.13m = 10.423J
RGC 150, 80mm spread, set to 20mm block set:
W = (68.04kg * 9.81m/s^2 * 0.0036m) / 0.16m = 15.0181J

@C8Myotome This captures in a single number what you also explained.

@Cannon This is what you meant by " the narrow gripper doesn't feel easier because the pounds at close isn't actually 100, but rather it feels easier because it was less total work to get to closed which ratings do not capture well". 

Edited October 10, 2023 by matek

[Cannon]

That is great info @matek. I will dig into this. We have seen a few ways to address the math and a few ways to skip math and get similar "work" outputs with instrument measurement. 

The thing that instantly gets fiddly is picking something to represent the strength. At first glance, open to close makes sense, but then that is the least common way to work with grippers. So do you pick a constant point? You could pick CCS width but some narrow grippers don't even have a CCS spread. So do you pick "work" from 30 mm? 20 mm? 

Then let's say you picked 20 mm to be the number on the rating tag. Immediately you have end-users saying this X is harder to CCS than Y even though they have the same tag. You're back to the same problem with current simple ratings even though you started with a more complex representation.

As I keep saying, this is a really interesting and complex problem to troubleshoot. Would love to hear your thoughts on how you pick essentially "what to put on the tag". (Never mind that if this was accomplished with computer-aided instrumentation you could send the gripper along with a sheet of specs that detailed tons of different values.) Love this discussion 

[C8Myotome]

I think RGC ratings are great and that they don't need to be changed, but rather it could be beneficial to include more information

What if a tag had RGC plus handle spread just as 2 data points (example: 100 RGC, 75 mm, or actually how about

RGC x handle spread (example 100x75 = 7500). I don't know what unit you would call this to represent RGC per millimeter, but this could be a single number (7500) that represents both RGC and how much handle spread had to be compressed to reach closed.

That would solve people wondering why 100 RGC of one spread or brand is easier or harder than 100 RGC from another brand or model...because it's not about just RGC, and anyone that takes 2 seconds to think about this knows this but for example people always compare heavy grips to CoC then have a harder time with CoC, so maybe for example...

100 RGC CoC with 75 mm spread = 7500 gripper

100 RGC Heavy Grips with 55 mm spread = 5500 gripper

you still might run into the issue of other combinations of RGC times spread resulting in the same "7500" or "5500" figures

For example you can still come up with the number 7500 by 90 RGC x 83 mm, 80 RGC x 93 mm, etc etc...these are very obviously different RGC combined with different spreads

So I'm not sure really

There's also the variation in handle width with none of these equations even touch on...A wider handle had the hand starting and finishing in a wider position

A narrow handle has the hand starting and finishing in a narrower position

Different people may find larger or smaller handles easier or harder depending on their build

I think RGC is fine still, I mean I already personally know and understand that one RGC number does not mean that the same RGC number means that another gripper has the same proportions and dimensions of the first gripper you described...it seems like we are doing all this math to still try to continue to explain to people why narrow grippers are just easier than wider grippers even when the closed RGC value is the same, because RGC does not capture spread. It seems like this is only a confusing concept for beginners and not people that are very into grippers who would understand this concept.

I would just write RGC and spread, and let people know wider spreads are harder than easier spreads...I don't think we really need Neil Degrasse Tyson for this

 

Edited October 10, 2023 by C8Myotome

[matek]

40 minutes ago, Cannon said:

That is great info @matek. I will dig into this. We have seen a few ways to address the math and a few ways to skip math and get similar "work" outputs with instrument measurement. 

The thing that instantly gets fiddly is picking something to represent the strength. At first glance, open to close makes sense, but then that is the least common way to work with grippers. So do you pick a constant point? You could pick CCS width but some narrow grippers don't even have a CCS spread. So do you pick "work" from 30 mm? 20 mm? 

Then let's say you picked 20 mm to be the number on the rating tag. Immediately you have end-users saying this X is harder to CCS than Y even though they have the same tag. You're back to the same problem with current simple ratings even though you started with a more complex representation.

As I keep saying, this is a really interesting and complex problem to troubleshoot. Would love to hear your thoughts on how you pick essentially "what to put on the tag". (Never mind that if this was accomplished with computer-aided instrumentation you could send the gripper along with a sheet of specs that detailed tons of different values.) Love this discussion 

RGC is the maximum force needed to close the gripper, while the concept of Work applied to grippers is about the "journey", the full effort. Of course, the measure itself is not understood as easily as RGC, because it's about energy. 

We can, but it would be somewhat arbitrary to combine these two metrics or come up with a new one (introducing a leverage factor for hand size, etc.) to represent "strength" because it's not a physics concept. 
In my opinion, RGC should be on the tags. Everybody just needs to understand what it measures and what it does not measure. And it's a big plus about it that it's very easy to understand. You put weights on the end of the gripper, and it closes at a certain point, that's it. 

The equation was more for gripper nerds , and it's proof of what everybody understands intuitively. 

[Scottex92]

16 minutes ago, C8Myotome said:

I would just write RGC and spread, and let people know wider spreads are harder than easier spreads...I don't think we really need Neil Degrasse Tyson for this

 

This is really simple and offers an option for microloading grippers (similar to filling but not exactly the same).

Jump from 150 RGC 65mm to 150RGC 70mm

[Carl Myerscough]

My widest gripper is also a coc #3 at 79mm. I measured it at 80 when I got it, but it has gotten a little narrower over time.

As many have said before generally if you line up several of the same # grippers the spread will correlate with the rating, wider = harder, particularly with coc and ghp where the mounts are pretty consistent. However it doesn't hold true if you compare older generations of grippers with new. For example I have a single stamp coc#4 purchased in 2003. It has the older blacker spring, and thus different properties. It rated at 216, and is only 71mm spread. However it is immensely harder through the first half of the range compared to a modern one. It took me much longer to close, I think I was at 3 reps with my 216 ghp before I got one with that.

Edited October 10, 2023 by Carl Myerscough
Removed aluminum

[matek]

2 minutes ago, Carl Myerscough said:

My widest gripper is also a coc #3 at 79mm. I measured it at 80 when I got it, but it has gotten a little narrower over time.

As many have said before generally if you line up several of the same # grippers the spread will correlate with the rating, wider = harder, particularly with coc and ghp where the mounts are pretty consistent. However it doesn't hold true if you compare older generations of grippers with new. For example I have a single stamp coc#4 purchased in 2003. It has the older blacker spring, I assume not aluminum, and thus different properties. It rated at 216, and is only 71mm spread. However it is immensely harder through the first half of the range compared to a modern one. It took me much longer to close, I think I was at 3 reps with my 216 ghp before I got one with that.

It is never aluminum, but I get your point.
This is what I meant by the force increasing linearly is just an assumption, and to get a more accurate measure, we would need to incorporate the spring constant; and for what we need the wire diameter, the mean diameter of spring, the exact number of active coils, and the modulus of rigidity for the material (e.g., oil-tempered spring steel). 

[Carl Myerscough]

Thanks for the correction

[Vinnie]

On 10/10/2023 at 9:44 AM, matek said:

With RGC, we are measuring the force required to overcome the resistance of the spring. So F = RGC * g. 

I don't understand this part quoted above, which is making me have trouble following the rest.  I mean, I got a 5 in AP physics, so I should be capable of understanding -- but it was 1986, so I think I probably forgot most of it and probably need a reminder (I'm a lawyer now and I don't use math much).

First question is, are you referencing g, the constant acceleration of gravity?  You didn't say so in that sentence, but then later you substitute the constant and talk about using grippers on earth, so I think it is what you mean.  But how does gravity have anything to do with the questions being examined about closing the gripper?  The resistance of the spring would be (at least substantially) the same in any other acceleration frame, and we are interested only in the close, not in whether the entire gripper and you are being pulled toward a massive object at the same time.  In other words, I would think a gripper would be just as easy or hard to close in free fall, or on Mars, wouldn't it?  I mean with negligible difference that we aren't trying to account for, anyway.

I am also confused by the integral.  If we are simplifying to make the assumption that the distance the gripper is closed is the chord rather than the arc, and that the distance covered when force is applied will correlate linearly with the force applied until force equal to RGC closes it fully, then why do we need the area between the handles?  Wouldn't applying half the RGC of the gripper just close it half way?

I am not asking these questions to suggest you are wrong about anything.  I am assuming I am misunderstanding something, because I am rusty, and am hoping to understand it.

[Vinnie]

3 minutes ago, Vinnie said:

I don't understand this part quoted above, which is making me have trouble following the rest.  I mean, I got a 5 in AP physics, so I should be capable of understanding -- but it was 1986, so I think I probably forgot most of it and probably need a reminder (I'm a lawyer now and I don't use math much).

First question is, are you referencing g, the constant acceleration of gravity?  You didn't say so in that sentence, but then later you substitute the constant and talk about using grippers on earth, so I think it is what you mean.  But how does gravity have anything to do with the questions being examined about closing the gripper?  The resistance of the spring would be (at least substantially) the same in any other acceleration frame, and we are interested only in the close, not in whether the entire gripper and you are being pulled toward a massive object at the same time.  In other words, I would think a gripper would be just as easy or hard to close in free fall, or on Mars, wouldn't it?  I mean with negligible difference that we aren't trying to account for, anyway.

I am also confused by the integral.  If we are simplifying to make the assumption that the distance the gripper is closed is the chord rather than the arc, and that the distance covered when force is applied will correlate linearly with the force applied until force equal to RGC closes it fully, then why do we need the area between the handles?  Wouldn't applying half the RGC of the gripper just close it half way?

I am not asking these questions to suggest you are wrong about anything.  I am assuming I am misunderstanding something, because I am rusty, and am hoping to understand it.

One thing that would be interesting, whatever the answers to these questions are, would be if Matt did an experiment and took some grippers of different spreads and measured how much weight closed the handles to ccs, 38mm, and 20mm, and fully closed (RGC).  If he's measuring by ruler and eyeball it won't be perfect, but it might be enough to give a sense of how linear this is (or isn't).