The plastic guard serves an extremely important purpose!




To keep someone from suing the bike company. Same as the little tabs on your fork that prevent you from using a quick release, wheel reflectors that cause massive vibrations at any kind of speed, etc. There's already a device to prevent your chain from going into your spokes, it's called a limit screw.

 

upgrade to a carbon fiber one.

 

where do you find those? Link?

 

Just go with a solid rear wheel. The cool factor would be over the top...

 

The plastic disk is lovingly referred to as a "dork disk." It may be removed without harming you bike in the least.

I am more concerned about the rest of your bike. That had to be a pretty hard knock to break that disk.

Did you check the whole thing over? Wheels true? bolts/nuts tight? Lose anything important?

 

cyyoung749, you may hear it referred to around here as a "dork disk". The purpose of the guard is to keep the chain from over shifting into the spokes by accident. As enzo24 points out, though, as long as the derailleur is adjusted properly that kind of over shifting is very unlikely to happen.

Having said that, since your disk broke as a result of your bike falling over, you can remove it and don't need to replace it, but make sure your derailleur is still properly aligned.

 

The purpose of the guard is to keep the chain from over shifting into the spokes by accident.

Nope, it's to prevent the spokes being nicked by the chain if it ever derails over the top of the cogs. Only limit screws (properly set!) will do what you say.

 

I took the "pie pan" off my bike before it left the shop!! It was SO ugly. Twice as big as it needed to be.

I've heard that if you somehow bend the derailleur hanger it can cause the chain to flip off the big cog even if the limit screw is set properly

 

Yeah, my old Nishiki still has that huge thing on it. I have often considered removing, but I am trying to keep it original, even if it looks dorky. Speaking of dorky: I was riding with our group the other day and a new member showed up with a new Felt that was still wearing all the reflectors. Haven't seen that for a while.

 

Funny, I am restoring my old Nishiki Royal 15 too and I am trying to keep it as close to original too. I will probably not keep the dork disk though, but I would like to keep the dealer sticker from La Mesa Cyclery in La Mesa, CA and the base sticker from 32nd St Naval Station because they actually mean something to me. I liked that bike shop and it is now a carpet sales place and I haven't been in the Navy since 1995. I'll keep it a triple crank too because I intend to load it up with panniers and use if for my long distance riding and commuting once it is finished.

I won't keep the wheel reflectors though, I have been north of 50 mph on my old Nishiki and I could definitely tell there were reflectors on the spokes back when that bike was brand new. I took them off at the bottom of the Cuyamaca grade in SD near the stadium because the made the bike squirrelly at that speed. Without them, I managed to get a speeding ticket for going more than 60 mph down that same hill about a month after I bought the bike. Ya gotta love CroMoly steel, that bike was as stable as a Ferrarri at that speed!

 

The bike fell and only the disk broke? How is that possible?

 

Mandatory things to be removed from a bike before being seen in public are:
Bells
Wheel reflectors
LBS stickers
and YES - Spoke protectors...

 

Add to that list the ridiculous amount of yellow warning stickers I found on my wife's new Specialized.

 

The plastic guard serves an extremely important purpose!

It allows other riders to know who the noobs are.

That, and reflectors, and a two gallon seat bag.
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.
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I think they're acceptable IF they are not larger than your biggest cog, and preferably clear.
But when they look like this? WTF!

 

OP Send the bike back to Trek for a replacment.

 

Normally a safe assumption, but every so often it's a good idea to go into a profile and look at a noob's prior posts. :wink5:

You mean Giant.

 

To the OP who asked whether the spoke protector disc is really needed, it depends on who you'd ask. From the viewpoint of the Feds, refer to this link I stumbled upon:

Recall

Be the judge.

 

just take the useless piece of crap off.

and the spoke reflectors and the kick stand if you have those...

 

Dude! Get that thing replaced ASAP! If 5.0 catches you out riding with no spoke protector it's a hefty fine and they'll likley impound your bike.

 

You could always do this. But use Carbon Fiber rope and be uber cool.

 

Hahahaha that ****ing halarious

 

Won't a carbon fiber spoke protector be prone to exploding when exposed to direct sunlight?

 

Only if it got wet first.

 

After installing a friends cassette on a new wheel for him, he informed me that he wanted the plastic disc put on his bike. I had left it off. But I was more than happy to oblige after some modification.

 

Tough love > no love

 

lol, I must be a total noob! I had no idea there was such stigma associated with keeping the "dork disk" on or that it was even referred to as a dork disk, or what supposed purpose, aside from signaling dorkiness, that it was trying to serve.

Whew, that was a mouthful!

Okay, so got it on the dork disk, but what's so bad about the spoke reflectors? If you happen to get caught out at night, won't they serve some purpose, if you don't have a proper front and rear light?

 

Okay, so got it on the dork disk, but what's so bad about the spoke reflectors? If you happen to get caught out at night, won't they serve some purpose, if you don't have a proper front and rear light?

They throw the wheel off-balance. As speed increases so will the effect and after a certain speed is reached could actually become deangerous.

Some folks, myself included think they ruin the overall appearance of the bike. My LBS could take the DorkDisc off for me, but by law couldn't touch the reflectors - front, back and wheels. First thing I did when I got the bike home take the reflectors off.

My lights do an adequate job. I don't ride in pitch dark. If I do, I have a reflective vest just for that purpose.

If you want to keep the reflectors, if you feel safer with them on the bike rather than off, then by all means keep them. Aesthetics is one thing but personal safety is another and that is something you are personally responsible for. Do what you think is right.

 

Its so the chain wont fall into the spokes; are you sure? Hmm, I thought it was to help with aerodynamics, especially the really large ones.

 

You're kidding, right?

 

was wondering this myself, thanks for clearing up

 

Reflectors are useless. The front one would only help if you were riding on the wrong side of the road. The rear one isn't as effective as a flashing tail light. When headlights pick up spoke reflctors, the car is either far away, or about to T-bone you. Either way, the reflectors are useless.

 

Now that I have to agree with mpre. And since 99% of my rides are during daytime, those reflectors have no use for me as well.

 

Don't listen to anyone's advise regarding dork disks, saddle bags, etc. It really matters not what snap judgements other riders make about your gear. Get out and ride and enjoy yourself. Do it enough and you'll be able to pass a great many wanna-be racer boys that would otherwise mock you for having a saddle bag or a Trek with a bike shop sticker. Hey wait, my '07 Trek still has the dork disk, LBS sticker, and a saddle bag. Mods, can you change my username to "Fred" or "Freddy Faster Than You"?

 

If a wheel isn't true there will be movement of the rim from side to side when viewing the profile of the wheel; looking at it from the edge. This is solved by adjusting spoke tension to pull the rim into true.

Balance is if part of the wheel is heavier than other parts of the wheel. It causes the wheel to look or feel like it's oscillating when viewed from the side. The effect becomes worse as the wheel spins faster; you might never notice the imbalance from a wheel reflector at 20mph, but probably will at 50mph. As suggested above, put your bike into a stand and spin up a wheel. You'll probably notice that the bike is moving up and down in the stand; this is caused by wheel imbalance.

There is always some level of imbalance just from the weight of things like where the rim is joined. Some manufacturers (i.e. Fulcrum) make the section of the rim opposite the joint slightly heavier to compensate.

Fulcrum Dynamic Balance

In cars they solve for balance by crimping lead weights onto the rim.

 

ddmick, could it be that the up and down of the wheel you're referring to is called "roundness" or "dishing" and not balance? Let's be realistic: very few could reach speeds of 50mph on a bicycle and try to notice if there's shimmy on their wheels. That's outright dangerous and pure s7up1d granting that one's a pro and able to reach that speed. If your bike wheels are not true, you'll start to notice it right before you reach 10mph because it's rubbing on your brakes, or if it's out-of-round then you'll feel the thump-thump on your bike even on speeds as low as 12mph if you're that sensitive to your bike. Now if we consider that the wheel is reasonably true and properly dished, and yet it still favors one section by always resting there no matter how one tries to freely rotate it, then perhaps there's something wrong with the wheel material when it was made, hence it's a manufacturing defect. In this case, it's still not the cause of that lightweight reflector. Plain impossible.

So I'm still not convinced that a 10-gram reflector could cause the wheel to become out of round.