Gym lifting platform problem

[Andrey.]

Got gym membership very close to my home. I switched from the gym with a proper platform, but this gym is quite far. New gym has 2 lifting platforms covered with semi-hard rubber/foam material of about 1 inch thick, on top of the plywood. I can’t define the hardness at Shore hardness scale, but it compresses slightly if I push finger hard into it, and I can bend a piece of it from the side. Here’s the video: GOPR6434 - YouTube

I did deadlift at it and I’m not sure if I felt the squishiness (though it definitely felt different compared to wooden floor), the deadlift was harder to perform with the same weight compared to the wooden platform at a different gym few days ago though. The weight was even slightly less due to switching to kg plates, 310lbs vs 140kg (not sure if this attributable to platform, but I’m aware that I definitely lost some energy to squishiness). I’m yet to try squats (125kg) in weightlifting shoes which will definitely feel confusing (on a philosophical level) just due to the “hard shoes, squishy floor” combo (I deadlift in flat-soled non-compressible sneakers, but the soles of weightlifting shoes are still stiffer)

I definitely like wooden platform better, and I also like strictest technique because my piriformis can misbehave if I’ll introduce some slack, or asymmetry (but this probably can’t be caused by this platform), or different/unusual pulling angles in the movement — I also feel this now but again not sure if relates to platform

How critical is that the standing part of the platform isn’t completely hard? Maybe my weights aren’t high enough to bother?

[Mark Rippetoe]

This looks like stall mat to me. But your analysis is wrong. We don't care if a small contact patch deforms under point pressure. We care if the whole sole of your shoe is unstable under the load distributed across the entire area of the contact. Running shoes on wood are not stable, since they are not designed for stability. Lifting shoes against stall mat are stable, since the distributed weight of barbell/your body across the surface of the shoe soles is nowhere on that contact area sufficient to deform the stall mat.

[Andrey.]

I considered the point about full sole area pressure (and my size is US 11.5), this is what I hoped will allow me to lift on this platform. I guess it’s not a particularly frequent problem to have unstable surface, as compared to unstable shoes, and probably there aren't many existing gym surfaces which can introduce problematic instability — this would be something like shock absorbing mat from judo hall I guess?

In the past I saw square rubber mats in gyms which are very hard (couldn't be deformed by a finger), and when reading "a stall mat" I always considered it a similar mat. This thing is definitely softer as compared to those mats, but I don't know how hard stall mat is supposed to be. I googled "stall mat" and it indeed looks similar (actually I could ask them specifically what this mat is, but then I recalled about durometer!). I guess I won't be able to tell a difference, even if this mat would be suboptimal

[Mark Rippetoe]

Might be time to build your own gym.

[Andrey.]

Home gym is what I hope to build when I'll own a home. I identified this platform, it's a stock Matrix "Solid Rubber Surface” platform, described in their brochure on a screenshot at the bottom (web link: Matrix Fitness)

I suppose Matrix Fitness knows what they’re doing with this surface, though they market hardwood variant at almost double price for “optimum foot grip and stability during explosive Olympic lifts”

[Farmer]

I did deadlift at it and I’m not sure if I felt the squishiness (though it definitely felt different compared to wooden floor), the deadlift was harder to perform with the same weight compared to the wooden platform at a different gym few days ago though. The weight was even slightly less due to switching to kg plates, 310lbs vs 140kg

I think the odd are much higher that the plates weigh different amounts.
Factory globogym plates can be off by 5% or more.

Are the plates the exact same height? The ones in the video look like chinese-non-spec-Mattel-India-mart brand junk.
You'll see 18", 18.5", 450mm, 440mm diameters out there.
Height of the bar will affect things off the floor with the pull.
I've seen weird kilo sets like to where the 20kg and 25kg differ in height....by a ~cm.
(similar to how in cast-iron pound plates will vary in height from 25 to 35 to 45)

What are the differences in the bars at the two gyms?
A thinner bar will definitely bend more right off the floor and aid in pulling.

As far as the squishiness of the surface, if you are 200 lbs, you are already sinking in a bit before you pull.
Going to 510 (200+310) is only like 60% more weight. The material is only going to compress so much.


EDIT:
Googling around while typing this up .... if you have these plates:

Steel Herk Plates: Guma padengtas svoris 30mm inSPORTline Herk 20kg

yes, the 20's are only 40cm high.
The 25's are 42cm.
Most plates are 45cm.
That would do it.

[Andrey.]

Actually I'm about 200 lb (88 kg and will be heavier). Today I discovered that plates I used has 44 cm diameter, now I wonder how to deal with it (see link), I'll probably need to make gym owners to purchase some square rubber mats.

The plates has precise weight with 99.9% certainty as the gym is of an expensive/fancy type, and plates are made from steel which allows precise weight (as opposed to e.g. casted crude iron). Old gym also has steel plates which I weighed so they're also correct in weight. The bar was similar to the old gym, it had increased thickness (about 31 mm I think). My last hope was that bars were different in weight, but this also wasn't the case as I recently used a different 28 mm 20 kg bar with same results. I even considered testing my DL in the old gym to compare but figured I'll just put up with it

I'm certain that this slight 0.5 cm bar height difference did affect the lift to some degree, but I think the main reason was me not eating enough in that time period, as my squat also went down by a few kilograms.

[Mark Rippetoe]

The bar was similar to the old gym, it had increased thickness (about 31 mm I think). My last hope was that bars were different in weight, but this also wasn't the case as I recently used a different 28 mm 20 kg bar with same results. I even considered testing my DL in the old gym to compare but figured I'll just put up with it.

There is a big BIG difference between a 31mm bar and a 28.

[Andrey.]

What I meant is that I used thick bar for DL in both gyms, in the old gym I rarely used 28 mm and never felt a difference. In the new gym I only recently switched to 28 mm, again no difference felt (strap-less grip on 28 mm was easier though). All bars felt same on press, so this is my main indicator for the weight equality

[Andrey.]

It escalated. Now it's a problem to do a controlled drop in deadlift on this platform, because someone literally dropped (not a controlled drop) about 300 kg some time ago and something fell off of the ceiling at the 1st floor (the gym is at the 2nd floor).

They tell me to do it "easier", I try to explain that my 150 kg deadlift isn't a problem here (no problems reported during 5 months me lifting there, the problem was specifically the 300 kg drop). Though they still don't want to "limit" my ability to deadlift in their gym. So it's a shitty situation where they don't understand (I tried to explain) that they needed a platform with dampers instead, which is essentially Matrix Fitness representatives fault (they equipped the gym) — allowing to install hard deadlift platforms on the 2nd floor

They want to increase platform thickness. Am I right that this won't help, because as long as the hitting surface is hard it will transfer vibrations to the floor beneath it?

They also suggested I use bumper plates for DL — I didn't try yet, but will it cause the bar to jump into my face after I put it on the floor? (and bumper plates are stored far away from the platform)