What is the large round plastic piece behind the rear cogs called. It fits between the wheel and the cogs. I am looking for one for my bicycle. There are 5 cogs on the back, The wheel is a 27" x 1 1/4". I have tried to measure behind the cogs and from what I can gather the diameter of where the plastic piece fits is 38mm. Does anyone know where I could get these.

Thanks.

The technical name for that is "dork disk." If you put an ad in your local craigslist, you should be able to get one for free.

If I had a penny for every "dork disk" I threw away I'd be.....well, a few pennies richer.

They're formally known as spoke protectors. Easy to find via Google.

Why, may I ask, do you want one?
Most people just take them off. There's no need for one if your deraillers set up correctly. Manufacturers put them on in order to help prevent lawsuits from people running their deraillers into their spokes and injuring themselves.
Some of the old metal ones are pretty cool looking, but, still dorky.
-Gene-

SJS Cycles of England has them.

https://www.sjscycles.co.uk/product-S...-28T-10603.htm

If you are careful about keeping your rear derailer adjusted properly, you may never need one.

I want one as the bike had one on there originally and a I am putting it back to 100% original.

I've always called it a pie plate.

Ah, dork disks!



I'm thinking of putting one on a recently completed build as there's a fairly huge gap between the largest freewheel cog and the hub. Of course, on my first test ride, the chain came off over that cog and just about tour the spokes out. I think I had better adjust the derailleur and shift more carefully next time.

Neal

And I always thought in case of a breakdown you and your buds could play frizby to pass the time.

That is a fine collection of dishes!

What is the diameter of the hole that fits over the wheel. The ones I see for sale have a diameter of 35mm. But when I measure my wheel again it is just under 38mm.

The holes are all the same diameter.

This is a first. The guy wants to buy and install a dork disk!

No offense to the original poster, but you guys know you all wanted to say the same thing.

You're right.

Well if dork disks are such a terrible thing then why was one fitted originally. They are fitted on a lot of bikes that I have seen. There has been one fitted to my bike for over 15 years and I the bike shifted gear perfectly.

I think they look good, that is only my personal opinion which I am entitled to!!

Like I said, absolutely no offense to you. Indeed, you are entitled to your opinion and I will respect that.

BTW, have you ever wondered why they are called "Dork Disks?"

Spoke Protector is the correct name.
Dork Disks comes from an idiot's vocabulary.

That proves it! There are a lot of idiots on this forum.

But this part is still a dork disk.

I keep my "spoke protectors"on the bikes that came with them.I like keeping an old bike original even if it looks "dorky".I would not cut the fins off a 59 Cadillac because they are not in style any more.Some things look odd once they go out of style.By the way Goodwill had some old "bell bottom" jeans .I was thinking of resewing them to look like todays jeans.{not really}

Hell, I tore the dork disks off of my bikes when they were new. And they were called dork disks even that long ago.

Elegance is immortal, and so is extreme dorkiness.

Why don't Dorks like the disks?

This is getting fun now.

No, no, my dim witted friend. It's because only dorks ride bikes with dork disks. It is a sort of 1980's road nazi thing.

The first person to remove a Spoke Potector was called a Dork.

Why?, because he liked to hear the chain rubbing against the spokes.

Who was the first Dork?

Well, adopting your definition, whoever it was represented an evolutionary step forward.

gholian,see what you,ve started ! lol

I didn't start anything. I posted to get information on "spoke protectors". RFC made it personal. My 87 peugeot had one, doesn't mean there was something wrong with peugeot for fitting them. I would like to put one on it again to keep the bike original. My wife bought a new hybrid bike a few moment ago and believe it or not it has a spoke protector fitted! and believe this if you will the bike works fine!