What is this and do I need it?
03-15-20, 12:53 PM
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What is this and do I need it?
The plastic cover/guard looking thing between my cassette and the spokes.
03-15-20, 12:56 PM
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It's called a dork disc. It's meant to protect your chain from falling and damaging other components when it's on the biggest cog.
It's ugly and useless if your RD is adjusted properly.
It's ugly and useless if your RD is adjusted properly.
03-15-20, 12:58 PM
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So if I accidentally shifted past the big ring, the chain would fall off? I'm a relative noob and don't keep track of which ring I'm in.
03-15-20, 12:59 PM
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This is colloquially known as a “dork disc”. Don’t know what the official term is. If your derailleur is improperly adjusted or gets knocked during a fall, this disc protects the derailleur from getting caught in the spokes. Saves you money and possibly skin.
This one is kind of small, so it might just be there to keep the chain from jamming itself between the cassette and spokes.
I’d recommend keeping it.
EDIT: Too slow
”Properly adjusted” entails setting the “limit screws”, which will prevent you from overshifting. You’ll feel a hard stop if you try.
This one is kind of small, so it might just be there to keep the chain from jamming itself between the cassette and spokes.
I’d recommend keeping it.
EDIT: Too slow
”Properly adjusted” entails setting the “limit screws”, which will prevent you from overshifting. You’ll feel a hard stop if you try.
03-15-20, 01:03 PM
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This is colloquially known as a “dork disc”. Don’t know what the official term is. If your derailleur is improperly adjusted or gets knocked during a fall, this disc protects the derailleur from getting caught in the spokes. Saves you money and possibly skin.
This one is kind of small, so it might just be there to keep the chain from jamming itself between the cassette and spokes.
I’d recommend keeping it.
EDIT: Too slow
”Properly adjusted” entails setting the “limit screws”, which will prevent you from overshifting. You’ll feel a hard stop if you try.
This one is kind of small, so it might just be there to keep the chain from jamming itself between the cassette and spokes.
I’d recommend keeping it.
EDIT: Too slow
”Properly adjusted” entails setting the “limit screws”, which will prevent you from overshifting. You’ll feel a hard stop if you try.
Thanks; I guess I'll keep it then.
03-15-20, 01:36 PM
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If you are the type that doesn't fix anything till it's destroyed, then you need one. But if you don't find it aesthetically pleasing, and you or someone will investigate and find the cause of any chain or derailleur issues before it's a tragedy, then you don't need it.
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03-15-20, 04:07 PM
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supposedly it costs 2mph... this is from the source:
https://www.bikeforums.net/11975358-post2.html
https://www.bikeforums.net/11975358-post2.html
03-15-20, 04:18 PM
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All my bikes still wear them. I have never had a complaint from other riders----yet. lol
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03-15-20, 06:02 PM
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If you need to ask, you should keep it until you learn how to adjust your rear derailleur well enough that you don't need it anymore.
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03-16-20, 07:55 AM
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(dumb proof mechanism if you want). Try to downshift when your chain is on the lowest gear - it should be impossible mechanically speaking.
03-16-20, 08:44 AM
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It is not going to hurt your riding and could help you. I would keep it but that is up to you.
Frank.
Frank.
03-16-20, 07:47 PM
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I had kids that liked to imitate dad and they thought they understood how to adjust their own bikes DR's. The dork disc probably saved me from having to buy them a couple more bikes.
03-17-20, 08:07 AM
#14
mechanically sound
The least expensive way to shed a few grams from the bike is what I call it.
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03-18-20, 07:51 AM
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Mechanical paradox...
- If you need to ask, you need it
- If you know how to remove it, you don't need it
A little more explanation of what the guys are saying... Derailleurs have a few adjustments. One category of these is the limit of travel - Low and High, e.g. how far up and down the cassette the derailleur can move. These are set with screws. Sort of a "set and forget" thing in that they shouldn't need adjustment again, once set properly. If they are set properly, the chain can't drop off the backside of that largest cog - into the spokes - because the limit screw prevents that much movement/travel of the derailleur.
95% of "us" remove these "dork discs" pretty much the day we bring the bike or wheel set home. But... it's really not a big deal. Lots of these guys also care whether your sunglass arms are under or over your helmet straps. ;-)
- If you need to ask, you need it
- If you know how to remove it, you don't need it
A little more explanation of what the guys are saying... Derailleurs have a few adjustments. One category of these is the limit of travel - Low and High, e.g. how far up and down the cassette the derailleur can move. These are set with screws. Sort of a "set and forget" thing in that they shouldn't need adjustment again, once set properly. If they are set properly, the chain can't drop off the backside of that largest cog - into the spokes - because the limit screw prevents that much movement/travel of the derailleur.
95% of "us" remove these "dork discs" pretty much the day we bring the bike or wheel set home. But... it's really not a big deal. Lots of these guys also care whether your sunglass arms are under or over your helmet straps. ;-)
Last edited by Zaskar; 03-20-20 at 05:00 PM.
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03-18-20, 08:45 AM
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It protects your wheel spokes if your chain drops off the biggest cog into the gap between the spokes and the cogset. If you are climbing a hill with a lot of pressure on the pedals, chain drops off, and you really jam your chain in there, you can cause a good amount of damage to the wheel. Prob. called a "spoke protector" in a parts catalog. Just keep it there and forget about it. If you get to the Tour of Switzerland, have your chief mechanic double check your limit screws and take it off.
Last edited by grizzly59; 03-18-20 at 08:48 AM.
03-18-20, 09:49 AM
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supposedly it costs 2mph... this is from the source:
https://www.bikeforums.net/11975358-post2.html
https://www.bikeforums.net/11975358-post2.html
03-18-20, 10:23 AM
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I'm a dork, and I need a 10th post 
03-19-20, 11:26 AM
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03-19-20, 11:33 AM
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Mechanical paradox...
- If you need to ask, you need it
- If know how to remove it, you don't need it
A little more explanation of what the guys are saying... Derailleurs have a few adjustments. One category of these is the limit of travel - Low and High, e.g. how far up and down the cassette the derailleur can move. These are set with screws. Sort of a "set and forget" thing in that they shouldn't need adjustment again, once set properly. If they are set properly, the chain can't drop off the backside of that largest cog - into the spokes - because the limit screw prevents that much movement/travel of the derailleur.
95% of "us" remove these "dork discs" pretty much the day we bring the bike or wheel set home. But... it's really not a big deal. Lots of these guys also care whether your sunglass arms are under or over your helmet straps. ;-)
- If you need to ask, you need it
- If know how to remove it, you don't need it
A little more explanation of what the guys are saying... Derailleurs have a few adjustments. One category of these is the limit of travel - Low and High, e.g. how far up and down the cassette the derailleur can move. These are set with screws. Sort of a "set and forget" thing in that they shouldn't need adjustment again, once set properly. If they are set properly, the chain can't drop off the backside of that largest cog - into the spokes - because the limit screw prevents that much movement/travel of the derailleur.
95% of "us" remove these "dork discs" pretty much the day we bring the bike or wheel set home. But... it's really not a big deal. Lots of these guys also care whether your sunglass arms are under or over your helmet straps. ;-)
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03-25-20, 07:36 PM
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