PDA

View Full Version : Oly barbells, function of sleeves - newb



maxi
05-17-2008, 10:18 PM
Hey all,
I'm looking at buying a first olympic barbell and am trying to understand how the sleeves allow the weight plates to rotate freely. Sleeves means the same as collars, right?

From what I know, the inner side of the barbell is built up where the weight plates rest against, just like in a standard barbell, to stop the weight plates sliding towards your hands, so why then is an inner sleeve necessary?

The outer sleeves are designed to rotate freely but I don't understand how this forces the weight plates rotate. If the collars are removed, won't the weight plates be allowed to rotate freely anyway?

Runty
05-18-2008, 12:05 AM
You're wording is a bit confusing but the idea of the sleeves is to allow the plates to rotate freely from the part that you have contact with. Contact being hands grabbing to perform a press or deadlift, or on your back/traps for squatting. Collars(often spring coils) are used to keep the plates from sliding off the sleeves. Sleeves are the two ends that spin around but are connected to the bar. The reason you want the sleeves to be able to spin freely on the ends is because once the plates start spinning, they create a lot of torque. This also means it would require a lot of torque to spin them if they didn't rotate freely.

The weight of the plates themselves creates enough pressure that they don't spin very easily on their own. If you tried to clean 225lbs with free-spinning sleeves and then tried on a bar that didn't have them, you would probably break your wrists trying to rotate your hands over to get into the rack position.

Sleeves are not the same as collars.

maxi
05-18-2008, 01:00 AM
You're wording is a bit confusing but the idea of the sleeves is to allow the plates to rotate freely from the part that you have contact with. Contact being hands grabbing to perform a press or deadlift, or on your back/traps for squatting. Collars(often spring coils) are used to keep the plates from sliding off the sleeves. Sleeves are the two ends that spin around but are connected to the bar. The reason you want the sleeves to be able to spin freely on the ends is because once the plates start spinning, they create a lot of torque. This also means it would require a lot of torque to spin them if they didn't rotate freely.

The weight of the plates themselves creates enough pressure that they don't spin very easily on their own. If you tried to clean 225lbs with free-spinning sleeves and then tried on a bar that didn't have them, you would probably break your wrists trying to rotate your hands over to get into the rack position.

Sleeves are not the same as collars.

Hi Runty!

I'm really confused now! Are there videos or images to see what's going on? I realize that the sleeves are free to rotate over the thickest parts of the barbell where the diameter is 2 inches but I don't see the relationship between sleeves and weight plates.

I'm starting to think all the weight plates actually slide over the sleeves in their entirety, so if the sleeves rotate then so do all the plates together. Or do the sleeves just go on the outside like the collars and next to the collars?

Are sleeves an integrated, unremovable part of the barbell at the barbell ends? Or are they a separate component that can be taken off?

Rusty
05-18-2008, 05:29 AM
..............

The weight plates slide onto the sleeve and are held in place by collars, usually of the spring type in commercial gyms.

maxi
05-18-2008, 05:48 AM
..............

The weight plates slide onto the sleeve and are held in place by collars, usually of the spring type in commercial gyms.

Thanks Rusty. I didn't realize that whole outer length of 2" diameter was called the sleeve! I thought something external had to be slid over that outer section so you could change "sleeves" of a given barbell, if desired. So you're stuck with the barbell you get.

So all I have to check for when I buy a barbell is that the weight plates can freely spin. Since I can't clean properly and a deadlift won't involve much torque, would throwing up the barbell underarm like a power curl be sufficient to check?

Runty
05-18-2008, 06:16 PM
The weight of the plates once they are loaded on the sleeve is enough they don't slip on the sleeve. That is why the sleeve spins.

Watch in this video when the bar rests on his shoulders and is held over head. The plates keep spinning. That is because the sleeve itself is spinning, not because the plates are spinning on the sleeve.

If the sleeves didn't spin, it would be extremely difficult to stop the spinning and would twist the bar and your wrists with it.

1sA-lEbrgak&feature=related
http://youtube.com/watch?v=1sA-lEbrgak&feature=related

maxi
05-18-2008, 09:21 PM
The weight of the plates once they are loaded on the sleeve is enough they don't slip on the sleeve. That is why the sleeve spins.

Watch in this video when the bar rests on his shoulders and is held over head. The plates keep spinning. That is because the sleeve itself is spinning, not because the plates are spinning on the sleeve.

If the sleeves didn't spin, it would be extremely difficult to stop the spinning and would twist the bar and your wrists with it.

1sA-lEbrgak&feature=related


Gotcha! Great explanation :)

So I guess I wouldn't need to do anything fancy to test the condition of the sleeves I suppose, just a push to make sure they spin.

* But it's not really the sleeves that would be the problem, it would be the condition of the barbell that would determine if the sleeves rotate properly? i.e. if the barbell is bent or warped in some way.

maxi
05-19-2008, 06:10 AM
I got a good price for an oly barbell. It has "thrust bearings" so I figure it must be better than the other entry-level oly barbells I've been looking at that normally have "bushings".

I'm not sure if it's brand spanking new or if it's been used for store display. So besides checking that the sleeves rotate, is there anything else I need to look out for?

I mainly deadlift and sometimes do high-pulls (no olympic lifts) so if I dropped it, it would be accidental from around upper thigh height.