Bicycle Mechanics - I broke it, how important is this piece?

I took my less than 2 week old '07 Trek 3700 out for a ride yesterday and broke the little plastic disc that fits between the rear cassette and wheel. It is frustrating because I know I need special tools to remove the cassette to replace it or take it to a dealer to get it replaced. I called a Trek dealer yesterday and he said it is not a warranty part. :mad: He also said that a lot of people ride without them. I got a weed hung in it and it snapped off 1 of the little pegs that hold it on. Just out of curiousity, how important is this piece? Should I just have it removed or have another one put on? I am assuming it is there to keep chain lube off the spokes.

as long as your derailleur is adjusted properly, you can ride without it. It's there to prevent the chain from catching between your cassette and the spokes in case of an overshift. If the chain gets caught there, it can mess up all sorts of stuff.

Tear it off and keep the bike properly tuned.

Thanks. After I looked at it again that thought had crossed my mind on it's purpose. I tend to be rather anal about keeping things running perfectly whether it be bikes, cars, computers, etc. I guess that is the 10+ years as a cellular technician in me. Thanks again.

Learn how to properly adjust your Rdr.
Remove remainder of disk.

Most of us would remove it on purpose as soon as we got the bike.

Do a search on "dork disk". Think the answer is self evident in the title.

I took my less than 2 week old '07 Trek 3700 out for a ride yesterday and broke the little plastic disc that fits between the rear cassette and wheel. It is frustrating because I know I need special tools to remove the cassette to replace it or take it to a dealer to get it replaced. I called a Trek dealer yesterday and he said it is not a warranty part. :mad: He also said that a lot of people ride without them. I got a weed hung in it and it snapped off 1 of the little pegs that hold it on. Just out of curiousity, how important is this piece? Should I just have it removed or have another one put on? I am assuming it is there to keep chain lube off the spokes.


I would ask your dealer to point out the provision in the written Trek warranty that excludes the spoke protector. You might also ask him if the warranty will cover the cost of replacing the spokes if the chain should fall off the large rear cog.

The warranty on Trek's webpage says nothing about excluding spoke protectors. I suspect your dealer is incredibly lazy to not be willing to take five minutes to replace the item - especially since he probably has a bunch of them laying around that have been removed from wheels.

I would ask your dealer to point out the provision in the written Trek warranty that excludes the spoke protector. You might also ask him if the warranty will cover the cost of replacing the spokes if the chain should fall off the large rear cog.

The warranty on Trek's webpage says nothing about excluding spoke protectors. I suspect your dealer is incredibly lazy to not be willing to take five minutes to replace the item - especially since he probably has a bunch of them laying around that have been removed from wheels.

Unfortunately my dealer was closed so the dealer I contacted was not the dealer I bought it from. I called the dealer I bought it from today and was told I could bring it in for repair at no charge or he would remove it and leave it off for no charge.

Of all the things you could break on a bike, you got pretty lucky. As long as your derailleur is well adjusted, you should have no problems.

You just improved the bike... Cheapest upgrade!

Thanks. After I looked at it again that thought had crossed my mind on it's purpose. I tend to be rather anal about keeping things running perfectly whether it be bikes, cars, computers, etc. I guess that is the 10+ years as a cellular technician in me. Thanks again.

If you really are anal about keeping things running perfectly, then why don't you just invest US$10 in a cassette removal tool? The premise (first post) of this thread was that you would not be able to replace that plastic part, because you need "special tools". Well, buy that "special tool". It won't break the bank, and you can also help your friends that need to replace their cassettes (something that you'll have to do yourself, one day).

anal about keeping things running perfectly......10+ years as a cellular technician
As a cellular customer, I don't understand the correlation.;)

You could just take a pair of needlenose pliers and pull it out yourself.

If you really are anal about keeping things running perfectly, then why don't you just invest US$10 in a cassette removal tool? The premise (first post) of this thread was that you would not be able to replace that plastic part, because you need "special tools". Well, buy that "special tool". It won't break the bank, and you can also help your friends that need to replace their cassettes (something that you'll have to do yourself, one day).

He'll need to buy a chain whip as well as the lockring tool. Still a good investment.

He'll need to buy a chain whip as well as the lockring tool. Still a good investment.

In my opinion, an old chain will work just fine. Depending on my mood, it's sometimes even better than a chainwhip (I have been changing cassettes relatively frequently while switching to a new pair of wheels, sometimes ago).

You could just take a pair of needlenose pliers and pull it out yourself.

+1, that's exactly what I've done with all the bikes I've had...

Let's see, you broke the dork disk.......


oh well.

You just discovered why most people take them off. Eventually they will break. I had this happen twice, and both times it ruined that particular ride. I am much wiser now and would never own a bike with one on.

When i get a new bike that and the reflectors are the first thing to go, oh, and yeah...the saddle.

The plan was, and still is, to pick up the tools I would need just in case I need them in the future. However at the time I did not have them available. As for breaking them, well, I rode my Diamondback HARD for 9 years and the original disk is still on it and not cracked. That is why I was surprised when this one broke. I noticed that the one on the DB mounted differently though, it didn't have the cheap little tabs.

When i get a new bike that and the reflectors are the first thing to go, oh, and yeah...the saddle.


You ride without a saddle?? I'd like to see that. :-)

Sounds like there's a lot of anal guys in this thread :roflmao:

He'll need to buy a chain whip as well as the lockring tool. Still a good investment.

Just a note before he goes to buy tools-the 3700 has a freewheel, not a cassette... A shimano freewheel tool is just the ticket and cheaper if he really must remove/replace a $3 plastic disk.

Cassette tool and chainwhip are must haves anyway. gotta keep the importants parts clean :)

You're worried about a busted dork disc? Don't sweat it, and get yourself some cassette removal tools! Chainwhip, lockring tool and monkey wrench should set you back less than $20 all told.

Edit: I should mention that I find said tools invaluable for keeping things clean, and, for travel! To pack my folding bikes one thing I do is remove the cassette. So yeah, it's easy and takes no time at all!

Cassette tool and chainwhip are must haves anyway. gotta keep the importants parts clean :)

+1 for most of us who have a use for them but as I mentioned earlier OP needs a freewheel remover for the model bike he has...