T Nation

Size of Oly/Bumper Plates vs Iron?

I was wondering how the standard sized olympic and bumper plates compare to the common iron plates diameter-wise.

Chiefly I am curious as regards what range of motion is standard for deadlifts in a powerlifting meet. Would it be equivalent to a deadlift with a 45 iron plate? A 35?

Aren’t they the same?

[quote]Chewie wrote:
Aren’t they the same?[/quote]

Yes.

olympic bumpers are 450mm for competition (thank you google)

and I checked 3 different olympic plate companys and they are all roughly the same, might be off by like a fraction of a millimeter (thank you google)

I guess I need to go measure my plates then.

I just wanted to know what size iron plate (non olympic) matches up with the olympic plates (all the same diameter is my understanding) so that I know whether I am doing more of less ROM than a competition lift when lifting with a 45/35/etc non olympic plate.

They are all the same as the 45.

It’s all the same. That’s why bumpers are wider. I mix and match bumpers and iron all the time and If I have a bumper on my bar resting on the ground and then put an iron 45 on the same side, it slides on a bit more smoothly. So there is some difference but it’s so miniscule there is absolutely no reason for you to be obsessing over range of motion and what not.

Aren’t bumpers slightly larger, so you can use them with iron plates and not have to worry about the iron hitting the floor?

I think you are getting confused between Olympic vs standard plates rather than bumper plates vs iron.

Olympic plates are designed to fit an Olympic bar i.e. the sleeves are about 50mm diameter. The largest plates are about 450mm diameter as others have mentioned above. The difference between bumper and iron plates is that bumper plates will stay the same diameter down to at least the 10kg size so that the load is spread when dropping the bar to the floor. They are also wider to help with this as well.

On the other hand, iron plates will reduce in diameter with each reduction in weight. However they are still “Olympic” plates because of the type of bar they are used on.

Standard plates use the narrow diameter bars.