Smith machine not smooth

[Rottweiler59]

I’m stumped. I picked up a cheap smith machine. It’s old school. When I tried it at the guys house it seemed pretty smooth. It’s not counter balanced just simple Olympic bar dropped over the guide rods. Floor seems level, guide rods seem straight and I’ve greased it. I can’t think what else to do.
Any thoughts?

[gym62richard]

does it run on linear bearings?, did you have to disassemble the Smith to move it?, if yes.

A couple of thing's come to mind, is the unit level?, if not any misalignment of the guide rods could be an issue. Did you check that the guide rods were straight, any distortion could be an issue. Did you run the guide rod through the individual linear bearings before assembly, if yes, did you notice any wear/play in the bearings?, if any crap got into the bearing when the guide rod was removed wouldn't help. Are the guide rods really clean, with no rust spots on the chrome?. Did you replace the guide rods on the same side as when you first tried the machine.

What I've found with linear bearing/guide rod set up's, it's crucial that the guide rods are absolutely parallel to each other and run in the same perpendicular plane.

[Asjogren]

I’m stumped. I picked up a cheap smith machine. It’s old school. When I tried it at the guys house it seemed pretty smooth. It’s not counter balanced just simple Olympic bar dropped over the guide rods. Floor seems level, guide rods seem straight and I’ve greased it. I can’t think what else to do.
Any thoughts?

No grease...Teflon based spray lubricant...and as previously stated,the rods should be plumb and parallel

[gym62richard]

No grease...Teflon based spray lubricant...and as previously stated,the rods should be plumb and parallel

If the Smith has linear bearings, I was told teflon/silicone/graphite lubricant isn't recommended, these lubricants do help to reduce friction on the guide rod, however they can impact the ball bearings ability to move within the housing, thus creating friction.

There are a number of specific grease/oil based products that are recommended by bearing manufacturers, depending on the bearings application, will dictates the type of lubricant to use.

I was told for linear bearings used in gym applications, then a coat of light machine oil would be sufficient.

Of course if the Smith bar runs on bushings, then a teflon type lubricant should work well.

[Rottweiler59]

does it run on linear bearings?, did you have to disassemble the Smith to move it?, if yes.

A couple of thing's come to mind, is the unit level?, if not any misalignment of the guide rods could be an issue. Did you check that the guide rods were straight, any distortion could be an issue. Did you run the guide rod through the individual linear bearings before assembly, if yes, did you notice any wear/play in the bearings?, if any crap got into the bearing when the guide rod was removed wouldn't help. Are the guide rods really clean, with no rust spots on the chrome?. Did you replace the guide rods on the same side as when you first tried the machine.

What I've found with linear bearing/guide rod set up's, it's crucial that the guide rods are absolutely parallel to each other and run in the same perpendicular plane.

actually one thing I didn’t think of was which guide rod was originally in which part of the frame. Hmm that could be a factor. Add to the fact now I’ve looked at it again the tolerance over the guide rods is so tight that if not perfectly aligned I think it will catch. Thanks.

[Asjogren]

If the Smith has linear bearings, I was told teflon/silicone/graphite lubricant isn't recommended, these lubricants do help to reduce friction on the guide rod, however they can impact the ball bearings ability to move within the housing, thus creating friction.

There are a number of specific grease/oil based products that are recommended by bearing manufacturers, depending on the bearings application, will dictates the type of lubricant to use.

I was told for linear bearings used in gym applications, then a coat of light machine oil would be sufficient.

Of course if the Smith bar runs on bushings, then a teflon type lubricant should work well.

I agree. I should have been more clear.i don’t like the grease as it attracts dirt..I use Teflon on the rods and wipe them down . Light bearing oil( not a lot) on the linear bearings

[Duplicitous]

actually one thing I didn’t think of was which guide rod was originally in which part of the frame. Hmm that could be a factor. Add to the fact now I’ve looked at it again the tolerance over the guide rods is so tight that if not perfectly aligned I think it will catch. Thanks.

If they're linear bearings and you move the carriage with them misaligned, they can become irreparably damaged very easily. You will know it if it happens though as they will audibly scrape.

[Rottweiler59]

If they're linear bearings and you move the carriage with them misaligned, they can become irreparably damaged very easily. You will know it if it happens though as they will audibly scrape.

thank you I didn’t know that. Could be the issue then sadly

[Duplicitous]

thank you I didn’t know that. Could be the issue then sadly

Make? Have a pic of the machine?