In the past I've always tossed these things. But recently I put on a new rear wheel sans SP and now the RD is tinkling the spokes before FINALLY jumping to the big cog - I sound like Skippy the ice cream truck

I'll probably be removing this (5 speed) freewheel soon to replace it (6 speed) - do I really need to put a stinkin' spoke protector on??

BTW this is an old Schwinn Continental I'm resurrecting.

Your RD should not be touching the spokes. Because it is touching, and because you suggest shifting is slow to the large cog, I'd check the derailleur hanger for correct alignment. If the hanger alignment checks out okay, then possibly there's an issue with a bent derailleur cage?

I keep mine on. The extra few grams for a dork disc everyday is well worth preventing a $200 repair bill after the rear derailleur getting tossed into the spokes. However, as desertdork said, probably an issue with the RD or Hanger, not the lack of a spoke protector.

The spoke protector is to prevent the RD from engaging the spokes and being destroyed, It isn't necessary, but for low end RDs or bikes where decent maintenance isn't expected, (like dept. store bikes) it can save the owner serious grief if, for example, he drops the bike and bends the hanger. Spoke protectors aren't a substitute for proper RD adjustment, they just help lower the consequences of poor care. If you're diligent about maintenance, you can probably live without the safety net they provide.

In the OPs case, it won't help at all. Since the RD is touching the spokes (never a good scenario) the added loss of space to the spoke protector can only make things worse. Solve the problem by finding out why the RD is touching the spokes, such as a bent hanger or RD cage, and deal with that. Then you can decide if you want the added protection the spoke protector might offer.

Trust me. You don't want to shift your RD into the Spokes!
My wife did it once when we were on tour.
Knocked the wheel out of true, and bent the RD to a pretzel.

Caused a long walk.

If you can't fix it, your LBS can.
Don't ride your bike the way it is.

As one that feels they take decent enough care of my bikes but doesn't check the limit screws every other month either I managed to have a chain on a road bike drop inside the big rear sprocket. There wasn't a single re-useable spoke on that side of the wheel when the crunching stopped. It has happened occasionally on other bikes while shifting under more load than I guess I should have been appying and the odd time a stick during a trail ride tosses the chain off to the inside of the cassete. Thanks to dork discs these subsequent near disasters were but a moments work to put right instead of a long walk home with a mortally wounded bike. ALL my bikes proudly wear dork discs now. If I could buy a shirt that said "I <3 my dork discs" I'd get two of them.

But in no case do any of my rear derrailluers come anywhere near to rubbing on the dork discs or the spokes. I'd bet $10's that your derrailleur hanger is badly tweaked and the cage is leaning way inwards as a result.

Spoke protectors are cheap insurance; there's a post on here where a guy returned to his parked bike which had the dérailluer bent by 'parking rash'. Rode off and damaged the bike.

They're called 'dork discs' because only dorks remove them

I can't see that they hurt anything -- but I have seen enough broken and bent pie-plates that probably cause more problems than what their intended to prevent.

I've never ridden with the damned things and I've never had a problem.

Update - it seems I had the derailleur spring tension too high; backed it off and the problem went away. I'm sure my gas pipe boat anchor will ride like a dream now!

Same here. Let's face it, stuff happens. Cheap insurance. Besides, they're sexy.

Some of those old schwinns had large steel spoke protectors , there were some clear plastic ones that will be quieter and weigh less.
But by now the dominance of the cassette gear cluster , the freewheel spoke protector need protecting

from getting Dumped by teenagers given the job of clearing out the old stuff without knowing what anything outside of the game-boy is.

This was a large steel one, probably useful in combat.
I was a teenager when this bike was new!

Campagnolo used to make a spoke protector .. its part #55 in my old catalog..

rebuild that old Schwinn's rear wheel with an internal gear hub and life will get simpler.
you have to spread the frame to fit a 6 speed freewheel in, they went wider all the time, to keep newifying the market.

Get a Nexus 8 speed hub laced into the rim size, I expect its 27" and then only need one chainring on the front.

Agreed, the spoke protector on my Surly Big Dummy failed within about 3 months causing drag on the freehub cassette when coasting or back pedaling. If bad enough this can damage a derailleur too.

I can see the little snap teeth breaking off and allowing the disc to scuff away at the freehub. But come on now, how's the whole disc going to come off and damage or jam the derrailleur?