Any theories as to why some implants take way more pumps than others ?

[Bluewhippet]

I realise that my AMS CX is small, only 15 cm (4cm RTE) but after 18 months I can only get 15 full wall to wall pumps before the pump is too hard to depress any more. After a few minutes I can sometimes get one or two more partial pumps.
When the cylinders are fully deflated they are not flat so when pumping you are not refilling them rather pumping to straighten out any dog ears (wrinkles) and then inflating and increasing the pressure.
My surgeon told me that you are only pumping about 25 cc of saline when inflating which correlates closely with 12 to 15 full pumps.
I assume larger implants would require slightly more pumps but you are still not fully refilling the cylinders rather just straightening them inflating and pressurising them.
I understand that AMS MS Pumps are a bit larger than Coloplast pumps so may need less pumps.

[merrix]

I realise that my AMS CX is small, only 15 cm (4cm RTE) but after 18 months I can only get 15 full wall to wall pumps before the pump is too hard to depress any more. After a few minutes I can sometimes get one or two more partial pumps.
When the cylinders are fully deflated they are not flat so when pumping you are not refilling them rather pumping to straighten out any dog ears (wrinkles) and then inflating and increasing the pressure.
My surgeon told me that you are only pumping about 25 cc of saline when inflating which correlates closely with 12 to 15 full pumps.
I assume larger implants would require slightly more pumps but you are still not fully refilling the cylinders rather just straightening them inflating and pressurising them.
I understand that AMS MS Pumps are a bit larger than Coloplast pumps so may need less pumps.

If I am not completely mistaken, you mean 2.5 cc, not 25 cc.
Anyway, your data matches mine very well.
You get 15 full pumps.
Your implant has roughly half the inflatable length of mine (10 vs 19 cm), and your diameter is 18 mm vs 23 mm (I think) for a 24 cm Titan.
That would mean that my implant would need 19/10 * 1.15^2/0.9^2 = 3.1 times more saline.
If you get 15 full pumps, I would get 15*3.1=47 pumps.
Adding the fact that, as you say, AMS pumps are larger, I would need even more than 47.
Which matches very well with my experience.

[Evinrude]

I did this. It took me 40 full pumps to get to 100 ml, meaning one pump contains 2.5.

I also do know that Eid does underfill reservoirs to the exact amount needed, to make the reservoir as small as possible and minimize the risk for autofill. But still, if he would only put <75 cc in the reservoir, he would have chosene the 75 cc model, not the 125 cc.
So we can assume I have anywhere between 75 and 125 cc.
Let us assume 100.
That takes 40 theoretically perfect pumps. Something you wi
So what you say is completely impossible. Period.

So for you to say that nobody ever needs more than 14 pumps is just utter BS.
Either the guy who told you this simply doesn't have a clue.
Or you misunderstood him.
Or you deliberatley spread misinformation (quite unlikely, though theoretically possible)
Or the guy who told you didn't want to hurt your feelings by making you realize that what you call a rock hard dick is in reality just a semi filled implant, and some guys can inflate it way more.
Or... there are surely several other possible explanations as well.

But facts are you are wrong.
Go ahead and make the same experiment yourself and let me know your results...
And if you don't bother, please explain where my logic fails.

Did not misunderstand him... I was a little surprised as well so asked him twice more. You both make sense so I don’t know what to think. This week I’ll try and make contact to see what his response is to your counterpoint

[trlewis35]

On July 24, 2019, I was implanted with the AMS 700 CX 19cm with the MS pump. It takes 15-19 pumps to get the pump so hard I can't compress it at all. Tomorrow will be 2 weeks that been cycling and I've seen some gains in size which I believe maybe the 19 pumps I got this morning when I cycled it. Anyway, maybe the 15 range is normal for these units. Opinions from others with this unit would be nice.

[Bluewhippet]

To clarify Merrix, I meant a total of 25 cc. I understand that the AMS MS pump theoretically delivers 2 cc each full squeeze. Probably a bit less in practice since when pumping it is difficult to get it completely flat. My experience appears to be similar to triewis35 who also has an AMS CX, albeit larger. Presumably AMS LGX take more since they can also expand in length.

[Evinrude]

This content of your post is utter bullshit. Simple as that. There is no #¤&#& way that no implant, regardless of size, never needs more than 14 pumps. I am living proof of that, and so are several others here.
If I do 14 full pumps, squeezing my pump till it collapes wall to wall, I will not even get hard enough to penetrate. I will get a semi of the kind I had before surgery.


I did this. It took me 40 full pumps to get to 100 ml, meaning one pump contains 2.5 ml of water/saline.
That would mean that a full reservoir of 125 ml would take 50 pumps.
I don't know how much saline Eid actually filled my 125 cc reservoir with, but since there are two sizes, 75 cc and 125 cc, we can assume that some cylinder sizes do need more than 75 cc. If not, there would be no 125 cc reservoir on the market...

I spoke with one of Broderick's RN's today and where the max 14 pump figure comes from is the doctor pumping the penis to "bicycle tire" stiffness during the surgery. (Broderick is considered a "high volume" penile implant surgeon..does about 150 per year) He figures after a year of cycling three times a week the LGX gains in length and girth might account for another 3 or 4 pumps beyond 14.

He frankly had no explanation for your 40 pumps other than perhaps you have a tiny leak ! Which judging from your implant being over three years ago seems highly unlikely as you'd be "out of gas" by now if that were the case. So, once again...beats the heck out of me what the deal is... I believe you, but he sure sounds credible as well.

[merrix]

This content of your post is utter bullshit. Simple as that. There is no #¤&#& way that no implant, regardless of size, never needs more than 14 pumps. I am living proof of that, and so are several others here.
If I do 14 full pumps, squeezing my pump till it collapes wall to wall, I will not even get hard enough to penetrate. I will get a semi of the kind I had before surgery.


I did this. It took me 40 full pumps to get to 100 ml, meaning one pump contains 2.5 ml of water/saline.
That would mean that a full reservoir of 125 ml would take 50 pumps.
I don't know how much saline Eid actually filled my 125 cc reservoir with, but since there are two sizes, 75 cc and 125 cc, we can assume that some cylinder sizes do need more than 75 cc. If not, there would be no 125 cc reservoir on the market...

I spoke with one of Broderick's RN's today and where the max 14 pump figure comes from is the doctor pumping the penis to "bicycle tire" stiffness during the surgery. (Broderick is considered a "high volume" penile implant surgeon..does about 150 per year) He figures after a year of cycling three times a week the LGX gains in length and girth might account for another 3 or 4 pumps beyond 14.

He frankly had no explanation for your 40 pumps other than perhaps you have a tiny leak ! Which judging from your implant being over three years ago seems highly unlikely as you'd be "out of gas" by now if that were the case. So, once again...beats the heck out of me what the deal is... I believe you, but he sure sounds credible as well.

I find that very, very strange. Sure, you have a surgeon saying this is the case.
On the other hand, I know what I see and what I do with my own dick.
Lately, I don't use full wall to wall pumps. For two reasons:
One: It is faster to do more partials than to do fewe full pumps.
Second: I think doing full pumps will over time wear the pump down faster.
But just to prove my point again, yesterday I pumped my dick up with full pumps. I got to 43 before the pump got so hard I couldn't do full wall to walls anymore.
And I can guarantee you that those pumps were wall to wall.
43 pumps would be 107 cc, which would explain why I have a 125 cc reservoir and not a 75 cc.
Also, again, the mathematical evidence is that the pump only contains 2.5 cc. If nobody could ever do more than 17 pumps, i.e. 42.5 cc, why then are there 125 cc reservoirs on the market? Why are there even 75 cc reservoirs? 50 cc would be enough...

Just doesn't make any sense...

[Evinrude]

Just doesn't make any sense...

I agree...it is quite the mystery. Would be interesting to know what the other high volume penile implant surgeons have to say about pump numbers.

[Lost Sheep]

How many pumps do you need to do to move 125 ml?
Well, one simple way to test is to take a Titan pump, fill it with water, pour the water into a container and repeat till you have got to 125 ml...

I did this. It took me 40 full pumps to get to 100 ml, meaning one pump contains 2.5 ml of water/saline.
That would mean that a full reservoir of 125 ml would take 50 pumps.

Where did you (and where do you think I can) get a Titan pump (or an AMS pump) to do this test?

[Lost Sheep]

Here's a guess as to how a guy can get to full erection in less than a half-dozen squeezes of the pump bulb: He is starting partially inflated? His tunica is thick-walled and the implant does not require the full contents of the reservoir to hit THAT limit (that is, the inflatable tubes never need to reach their full diameter to make the penis rigid)?

Would anyone care to check this math?

Volume of a sphere is 4/3 PI times r cubed
my pump bulb is about 25mm in diameter
subtract .5 mm for wall thickness (on the thin side, perhaps)
inside diameter would be 24mm
24 mm diameter
Volume of my pump, then
7.238229474 cc total volume
let us suppose 90% efficiency for wall-to-wall pumps
0.9 efficiency
6.514406526 cc per squeeze
to move 100 cc would take
15.35059251 pumps
let us suppose 30% efficiency (small squeezes)
0.3 efficiency
2.171468842 cc per squeeze
46.05177752 pumps


Here are the formulas I used (copy and paste into your favorite spreadsheet starting at cell C6)

Volume of a sphere is 4/3 PI times r cubed
my pump bulb is about 25mm in diameter
subtract .5 mm for wall thickness (on the thin side, perhaps)
inside diameter would be 24mm
24 mm diameter
Volume of my pump, then
=4/3*(C10/20)^3*PI() cc total volume
let us suppose 90% efficiency for wall-to-wall pumps
0.9 efficiency
=+C14*C12 cc per squeeze
to move 100 cc would take
=100/C15 pumps
let us suppose 30% efficiency (small squeezes)
0.3 efficiency
=+C19*C12 cc per squeeze
=100/C20 45 pumps