Ask Levi: What Is That Plastic Disc on My 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, and it is sometimes called a “dork disc” because serious riders always remove those before riding a new bike. Apparently, shaving your legs and dressing in colorful spandex is cool, but a spoke protector makes you a dork! 😉

The purpose of the spoke protector is to keep the chain from shifting into the spokes and damaging the rear wheel and/or causing you to crash. It 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 into the spokes, and if that were to happen, I doubt that thin piece of plastic would help at all. It would probably get torn apart by the chain (which could be good, but it probably won’t save the wheel.)

I suggest removing it. It adds needless weight to your bike, it looks ugly, and it will do more harm than good. While I’ve never seen an accident caused by the 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.

(I highly doubt it will break and cause an accident any time soon, but there’s always that slight chance.)

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 Cluster” or read “How to Replace a Cassette.”

The tools for this job will cost about $25-50 total, though. A bike shop would probably do this for a lower price if you want, or 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!

I would avoid bending and snapping it, since that could put too much force on your spokes.

So here’s what I would do:

1. See if the shop where you purchased the bicycle would remove the spoke protector for free. (Just keep in mind, they had to install it to avoid breaking the law.)

2. Wait until you need a new cassette and just have the spoke protector removed at that point.

3. Buy the necessary tools for cassette removal, because then you can remove the spoke protector safely, and when you need to replace the cassette or switch wheels, you can do it yourself and save some money in the long run.

4. If it’s really an eye sore, cut that thing off!

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

Coach Levi

Levi Bloom is an experienced endurance athlete who has been training and competing for over 17 years. A former Cat 1 road and mountain bike racer (professional class on the regional circuit), he is now a cycling coach (USA Cycling Level 3 Certified) and sports nutrition coach (Precision Nutrition Level 1 Certified).

coachlevi.com