Should I cut down my Nelson CSS poles??  

The standard length of CSS poles were 96".
I have never seen or heard of 120" poles. Possibly they were a special order at the time?

.
Dont cut them....if original.

holes
When I bought my omni, it was installed in a basement with low ceilings. The owners had neatly cut holes and put them up into those holes. It worked great for 40 years. Though I dont imagine you have 2 feet of space between your ceiling and the next floor. I imagine someone would pay dearly for those poles. Sell yours and buy the standard ones. Or just put yours away for the day you live in a tall ceilinged house again.

Offer an exchange
on Craig's list (or eBay ?).
Putting the world right, one little step at a time. Man overcomes entropy. . .

I know...
I don't want to cut them. Actually hadn't thought of holes in the ceiling! Now there's some lateral thinking. Barry I'm not sure the exact length...I imagine our new ceiling is 8'...not sure of the old place but they fit perfect with a little adjusting @ the bottom. I guess I will start looking for shorter poles...or digging out the Sawzall?!?

Measure them.
if they're 96" long then they are the standard length. This makes them the most common size.
If, however, they're longer than 96", then you have rare special order poles and I would not cut them down.
The idea of cutting holes in the ceiling isn't a bad idea because it would stablize the system, but it would difficult to move!
I have three poles that are shorter than 96" and they're smooth on both sides...possibly a special order length. (I have two assemblies). The above top pix are the shorter poles and one group of shelves are tghe standard 32" width and the right side is the rarier 46" width pieces!

Measured them
this morning, they are 108" so I guess my old ceilings were 9'. These are smooth on both side as well, I thought that's how they all were? For some reason I can't see DA Forum pics on my work computer, I will have a look when I get home...

Ididn't think about
moving them, that's a good point! Better be sure of the location if I go that route...

Those 108" inch long poles
are not common; I thought 96" was the max size.
But, honestly, I don't think too many people could use them, so if they don't work for you, go ahead and cut them down to 96", which is the standard, default length.
After all, the poles are the most commonly found pieces listed on eBay; and in my opinion, stuff like this is made to be used so adjust the height to suit your usage (after all, I suspect you're going to keep them, aren't you?)

Yeah..
I don't think I will ever sell them, I couldn't afford to buy them at auction price (I only paid $200 for the entire set). And chances are that I will always have 8' ceilings. SO they will be getting chopped. I will save the pieces as "extenders" if I ever have 9' ceilings again! Thanks for the information, very informative..

Good for you, ID
as long as they're not really 'museum pieces', it's appropriate to make an adjustment so you can actually USE them.
By the way, do you have instructions to assemble the rather complicated CSS? I have a great quality photocopy available. If you're interested, email me directly (barrymn1@msn.com)

CSS Trade
I have 4-96" poles and would be willing to trade you for 4 of your 108" poles, if you haven't cut them down yet. Only catch, would have to be a local trade. Either Zeeland or Ann Arbor MI, and anywhere in between.

Bummer!
I already cut them down and the shelves are up in the new house...there are 4 leftover chunks in the garage. I would have traded for sure. Ah well...

ID
Do you have a pix of your installation?
Here's my shorter bookshelf. They're 79 1/2" tall, are smooth and look like they were sized at the factory. Note that the left side are the standard 36" width but the right is the rarer 46" width.
(I took down the magazine shelf and replaced it with a regular shelf)