[Mr.Cranky]

What is the correct name for the (typically) plastic ring, that goes between the rear cassette and the spokes? Not all bikes seem to have them but I think I need one because my rear derailleur is so crap. I have no idea what they are called. I don't think it's a bash ring as they go on the front chainset, but it is pretty much the rear equivalent. Any ideas?

 

[Glide the Clyde]

Ahh, the dork disc. It is for protecting your spokes should the chain slip between the cassette and the spokes. If your RD is adjusted properly, this should not be a problem and most riders take them off by removing the cassette and sliding it off.

 

[Ken in KC]

Dork disc....

What is the correct name for the (typically) plastic ring, that goes between the rear cassette and the spokes? Not all bikes seem to have them but I think I need one because my rear derailleur is so crap. I have no idea what they are called. I don't think it's a bash ring as they go on the front chainset, but it is pretty much the rear equivalent. Any ideas?

It's a spoke protector. Having a crappy rear derailer doesn't require one. Not having an upper limit screw on the rear derailer will cause you to shift your chain in to the spokes.

Set the upper limit screw on the rear derailer properly and you don't really need one.

It's been a while since I had a wheel that came with one. I seem to recall keeping it on until the tabs broke and it was flopping around the hub. I pulled it off after that.

 

[bbrins]

I usually just leave them on until the tabs start breaking off. I had one save my spokes one time when I bent my derailleur, so just having a well adjusted derailleur is not necessarily the end of it.

 

[Mr.Cranky]

Dork disk, haha. Thanks, a quick look for "spoke protector" got me what I wanted. I spent ages searching for random alternatives.

And yeah, I'd rather have a dork disk than mess up my spokes. Kind of like wearing a helmet I guess. You don't need one til it's too late!

 

[elake]

Yeah, they are very useful when you first start riding technical terrain because it is only a matter of time before you hit your rear derailuer on something and bend either the RD, or the derailuer hanger and force the chain to go over the top of the biggest cog and into the spokes. My advise for beginners is to keep it on there until you use it a few times, which will cause all the tabs to break, then take it off.

 

[Bikinfoolferlife]

It's a spoke protector. Having a crappy rear derailer doesn't require one. Not having an upper limit screw on the rear derailer will cause you to shift your chain in to the spokes.

Set the upper limit screw on the rear derailer properly and you don't really need one.

It's been a while since I had a wheel that came with one. I seem to recall keeping it on until the tabs broke and it was flopping around the hub. I pulled it off after that.

The limit screw that affects the low gear is called a low limit screw....setting the high limit screw will do nothing to prevent your derailleur from going in the spokes.

PS I mention this so as to avoid confusion, since derailleur limit screws are marked (L)ow and (H)igh and a newb could confuse upper with high...

 

[JPark]

Set the upper limit screw on the rear derailer properly and you don't really need one.

So you've never bent a derailleur hanger, or had a twig kick up into the drivetrain and suck your derailleur into your spokes?
That being said, most of the applications I've seen are almost useless. But, if someone made a "dork disk" that actually worked(and lasted), I would install one.

 

[Ken in KC]

Sorry

The limit screw that affects the low gear is called a low limit screw....setting the high limit screw will do nothing to prevent your derailleur from going in the spokes.

PS I mention this so as to avoid confusion, since derailleur limit screws are marked (L)ow and (H)igh and a newb could confuse upper with high...

My bad. Thanks for clearing that up.

 

[Ken in KC]

I have...

So you've never bent a derailleur hanger, or had a twig kick up into the drivetrain and suck your derailleur into your spokes?
That being said, most of the applications I've seen are almost useless. But, if someone made a "dork disk" that actually worked(and lasted), I would install one.

Of course I have. But in those cases, a plastic disc that barely covers my cassette isn't likely to help nearly as much as throwing on the brakes and trying to minimize the damage caused by the combined rotational forces of the wheel/bike speed/me. The spoke protector is really there for mis-shifts, not for catastropihc drive train failures. In cases of major failure, the damage is often caused by the force of the chain hitting the spokes and not the shearing, metal on metal impacts that the spoke protector protects against.

So we're all clear: I'm not suggesting that they don't serve a purpose. I'm not suggesting that you ride without one if you don't want to. I am suggesting that they don't last very long and don't provide a tremendous amount of value compared to a properly adjusted rear derailer.

 

[JPark]

Of course I have. But in those cases, a plastic disc that barely covers my cassette isn't likely to help nearly as much as throwing on the brakes and trying to minimize the damage caused by the combined rotational forces of the wheel/bike speed/me. The spoke protector is really there for mis-shifts, not for catastropihc drive train failures. In cases of major failure, the damage is often caused by the force of the chain hitting the spokes and not the shearing, metal on metal impacts that the spoke protector protects against.

So we're all clear: I'm not suggesting that they don't serve a purpose. I'm not suggesting that you ride without one if you don't want to. I am suggesting that they don't last very long and don't provide a tremendous amount of value compared to a properly adjusted rear derailer.

I totally agree that the current versions are all but useless, but I see the cause of catostrophic damage/failure a little differently.
In every case I have experienced(far too many ) it has been the result of the derailleur being caught either directly, or by extension in the spokes. Locking the rear brake does work, but is often too little/too late. I think a larger, more durable disc, would all but eliminate this.

 

[firstcut]

haha for years and years i thought it was to protect from dirt and rocks lmao. Learn something new everyday.

 

[Frozenspokes]

I totally agree that the current versions are all but useless, but I see the cause of catostrophic damage/failure a little differently.
In every case I have experienced(far too many ) it has been the result of the derailleur being caught either directly, or by extension in the spokes. Locking the rear brake does work, but is often too little/too late. I think a larger, more durable disc, would all but eliminate this.

So, what do you suggest? Maybe we should just start getting solid disk rear wheels.

The spoke protector is there to protect the spokes in the case of a mis shift throwing the chain into the spokes. Nothing more. I have caught the derailuer in the spokes on two separate occasions. In neither case would a spoke protector have done anything to prevent this. Crap happens on the trail........

 

[ae111black]

Remember the "dork disk" if the 80's they were big, metal and ugly just what you guy's are looking for..... Go over to VRC and see if anyone has an extra one.....

 

[Glide the Clyde]

Remember the "dork disk" if the 80's they were big, metal and ugly just what you guy's are looking for..... Go over to VRC and see if anyone has an extra one.....

Here ya go...

Oh, and these were around way before the 80s

 

[ae111black]

Yah my bad.... I was refering to the mountain bikes of the 80's not "bikes" in general

 

[firstcut]

so are these discs online for sale? and if so do you have a link?

 

[Bikinfoolferlife]

Try this http://tinyurl.com/ydla5az