I tried searching the forums for this but it didn't turn up an answer.

Thanks in advance
Dennis

It's the plastic ring that manufacturers install on your rear wheel behind the cassette. Remove it and rejoice in your non-noobness...leave it and forever be ridiculed...the choice is yours...

Until your derailleur goes out of adjustment, and you shift it too hard, and it eats half your spokes, while self-destructing in process!

Otherwise known as a "dork disc"

Back away from the spoke protector - do not touch the spoke protector unless you swear that you understand why it was placed where it is and that you will maintain correct RD adjustment.

Note, however, that I'm living proof that it's possible to ride for 40 years on at least 15 bikes without a spoke protector, and without shifting the derailleur into the spokes.
Now that PINGPINGPINGPING you hear tomorrow will be my derailleur going into the spokes. You don't need the thing if you maintain your bike, but it doesn't hurt anything and can prevent a minor disaster.

more commonly known as a pie plate, unless I'm mistaken

Yeah, but the only thing worse than a destroyed rear wheel, a busted derailer, a bent frame, and a high speed faceplant that takes out 3 or 4 teeth is..... riding around with a noob ring!

It helps you maintain an erection.

except maybe having a noob ring on for so long that the plastic turns yellow and brittle?

+3

The spoke-protector (among other names) is to keep your rear-derailleur from flying into the spokes and destroying your wheel and/or causing a bad crash. Unless you fully understand how to set the stop-screws on your RD (rear-derailleur), and check the angle of the derailleur-hanger - leave it alone.

you are DEAD to me!

I'm all for taking off the pie plate and setting the RD limit screw properly, but want to nit pick that even in a worst case situation with the der and spokes you're really not going to have a face plant.

that is, unless you've got one of those new fangled front wheel drive bicycles...

Ditch it.

this may be why the springs of most derailleurs move the cage away from the wheel... in the sudden loss of cable tension the derailleur wouldn't SPROING into the spokes.

dork disc. quaint. love to see the guys with carbon Zipps and Mavic premium wheels come in to the bike shop looking for the spoke protectors, 'the really big ones'.

it's faintly hilarious when asked to install a dork disc on a 1,500 gram wheelset.

Hey, I didn't say it was ME......it was this, um, this friend of mine........

Cannondale issued a recall of a bunch of 2009 bikes after shipping them without dork disks.
https://www.cpsc.gov/cpscpub/prerel/prhtml09/09155.html

I wonder how many owners will actually take the bike back to get one installed.

I left mine on my hybrid. A feel apathetic towards it, since it's not adversely effecting the wheels performance and weighs what? Maybe a few ounces, big deal, my hybrid is a tank anyways.

....oh crap-on-a-biscuit! I just noticed I still have one of those unmentionables on one of my bikes!

Spray paint.

Mine is shiny silver, and I kind of like the way it looks on my vintage Cannondale.

I still don't comprehend the hatred over the spoke protector. I only removed mine because it cracked.

END GAME:

If you know how to keep your RD & RD-hanger adjusted, you can lose the spoke-protector safely. You'd know when.

If you don't - keep it on. It could save you a ton of money and trouble.

If any cyclist were to approach and laugh at you for having one - jam a stick in their spokes and tell 'em to grow up.

It could mean the chain ring mark on your right calf too.

The 'best' spoke protectors are chrome-plated steel.