Ask Levi: What Is That Plastic Disc on My Rear Wheel?

Did you buy a new bike and there’s some sort of plastic disc on the rear wheel?

Are you wondering what it is and why it’s there?

I have the answer!

That Plastic Disc on Your Rear Wheel…

Here is a question about a little problem that confounds anyone purchasing a new bicycle…

Hi there Levi! another newbie question… what’s this black plastic plate at the center rear wheel? what’s its purpose? how can i take it off? thanks again!

Sincerely,
Mr. Pete Plate

Hi Petey,

That plastic piece that looks like a pie plate is a spoke protector. All new bikes come with them pre-installed from the factory.

It is sometimes called a “dork disc” because serious riders often remove them before riding a new bike.

Apparently, shaving your legs and dressing in colorful spandex is cool, but a spoke protector makes you a dork!

Cycling is a funny sport sometimes 😉

Why is it there?

The purpose of the spoke protector is to prevent the chain from shifting into the spokes, damaging the rear wheel and causing you to crash.

Although that sounds useful, the dork disc is totally unnecessary if the rear derailleur is adjusted properly.

The derailleur would have to be totally out of adjustment to actually shift the chain up into the spokes, and if that were to happen, I doubt that thin piece of plastic would help much.

That said, if you purchased the bike from a department store, there is a very real possibility the shifting might not be adjusted properly. Or the rear derailleur won’t hold the adjustment. In either case, the spoke protector may serve its purpose!

What should I do about it?

If you purchased your bike from a reliable bike shop, or you have a good understanding of derailleurs and shifting, I would suggest removing the spoke protector (dork disk).

Here’s why I suggest removing it:

• It looks ugly.
• It adds needless weight to your bike.
• It will do more harm than good.

The aesthetics are self-explanatory. But how is a dork disc dangerous?

It might break. It’s just thin plastic after all.

While I’ve never seen an accident caused entirely by the fault of a plastic spoke protector, I have seen them break. The plastic gets brittle from the weather, and whenever it gets hit, it will crack.

If it’s not removed immediately after any damage, sharp plastic pieces could snap off and get stuck in your cassette and jam your chain, or maybe even slice your tire.

Those situations are bad for your bike, and depending on where you’re riding at the time, could cause a crash.

To be fair, I highly doubt that a brand new spoke protector will break and cause an accident any time soon. But there’s always that slight chance.

And if you end up with a real problem, like a stick in your spokes, that dork disc isn’t going to help.

How to Remove a Dork Disc

If you would prefer to remove the dork disc from your bike, here’s how to do it.

To take it off without risking any damage to your spokes, you will need to remove your cassette, pull the spoke protector off, then reinstall your cassette.

If you need a tutorial for that, check out “How to Replace a Cassette” at BikeRepairVideos.com.

The tools for this job will cost about $25-50 total, and I think that’s a good investment. But if money is tight, it might be cheaper to have a bike shop do the job for you.

You could always ask if the shop where you purchased the bicycle would remove the spoke protector for free.

(Do keep in mind that it was initially installed as a safety feature, for legal reasons, so it might be up to you to remove the dork disc.)

To take it off quickly, for free, you could use a Dremel or another cutting tool (wire cutters or tin snips, perhaps) to cut it off.

But bear in mind, you could damage the wheel if you’re not careful!

You could also bend it back and forth until it snaps into pieces.

Personally I would avoid bending and snapping it, since that could put too much force on your spokes, knocking your wheel out of alignment. Or you might only get part of it off.

But it’s your call – if it’s really an eye sore, cut that thing off!

You can always wait. The simplest course of action is to wait until you need a new cassette and just have the spoke protector removed at that point.

That’s when I would buy the necessary tools for cassette removal, because then you can remove the spoke protector safely, and anytime you need to replace the cassette or switch wheels, you can do it yourself and save some money in the long run.

Or you could forget about it and go for a ride. The choice is yours!

By Coach Levi on March 28, 2009   /   Road Cycling Articles   /   11 Comments

Tags: bike repair