CdCf

Perhaps we're talking about different things.
The disk I'm talking about is large enough to prevent a long derailer from entering the spokes.
It's around 10 inches in diameter, I would think.

khuon

Dork-discs, pieplates, wheel frisbees, spoke-protectors... They come in different sizes and design. Some are big enough to cover where a derailleur cage might hit and others (like the one on my roadbike) are so small that they're useless from the outset. Also, it seems that Mavic shipped at least two different designs of spoke protectors. The one I have is barely larger than a 23T cog and others I've seen on later model Ksyriums are much larger and uglier.

In the olde days, these things were made of metal and fastened in a much more secure fashion. Those were probably pretty effective and some of them looked pretty classy. Since around the late 1980s, spoke-protectors were being manufactured out of cheap flimsy or brittle plastic with only three or four clips that held them in place against the spokes although the ones on my Ksyrium seems to be mounted to the hub-body which makes it both more secure and more of a pain to extract. It's lucky it's barely noticable otherwise I would have actually spent some energy removing it. These would typically break leaving the disc to rattle about in your rear wheel with the potential to snag and do some of the very damage they were intended to prevent. They also became ugly-looking and almost begged to be discarded off the bike. The fact that they weren't very securely fastened to the wheel in the first place sort of betrays that they were not really intended to be permanant. With enough mileage, most of them end up becoming road or trail litter and most people who have had them break and fall off never feel compelled to install a replacement.

cycletourist

I wonder how long until some company starts marketing carbon fiber spoke protectors?

Matt Gaunt

You're never going to miss it if you have decent, well tuned shifters.

Mine snapped off a few weeks ago funnily enough and it looks so much better without it.

Why do you think none of the top end bikes have one from the factory?

Matt

cycletourist

this is only a guess but... maybe they are just covering their own butts? Or maybe the federal bike spec requires them? It would be interesting to find out.

2manybikes

If the drop out, or derailleur hanger, or the derailleur cage is bent, the chain can go right over the top cog. That particular problem has nothing to do with the screw being out of adjustment. It happens all the time. Even a loose wheel quick connect or a wheel put in slightly crooked can do this.

This is sometimes noticed during "proper maintenance". If it's minor you can adjust the screw for a temporary fix. If it's small enough even a permanent fix.

The number of bikes that come into the bike shop with this problem is surprisingly high. There was a certain brand of aluminum , made in USA bikes that a strong rider on a hill could bend the hanger just by stress on the chain. It used to happen during MS 150 rides and they would come into the rest stops for repair. because of shifting problems. Then we would realize the hanger was bent. It still happens on some bikes.

If the bike falls over on the derailleur side and you don't know, it could be ready to happen.

The high end bikes are often (not always) owned by riders who understand this and can fix it. Or they take the bike to the shop once in a while.

Don't ever think this could NEVER happen to me. Unllikely yes....never........no.

Applehead57

Yep, ignoring your spokes is a very effective way to induce your RD into the spokes.

Sometimes I learn about stuff before it bites me, sometimes........

2manybikes

I first learned the hard way. It bent the dropout around in a circle, destroyed the der. and some spokes. I was going maybe 5 mph. My wife said my bike looked like it was in a car accident Badly damaged the rear rack too..

.......sometimes....

roadfix

OK OK OK OK OK OK OK!!!!!!!! ENOUGH!....
Those who need the security of the disk may leave them on! And those who think they can go without, go ahead and take them off! I don't care what you do.
For those who want them off NOW!!.... simply take a pair of needle nosed pliers and break them off by nibbling at it piece by piece. They be off in 2 minutes.....

Avalanche325

Maybe the standard should be determined by this. Not if you are a novice or expert rider. But, if you are novice or expert at bike maintenance. If you do your own maintenance at proper intervals and are confident that you keep everything tuned up properly, take it off.

If you are the type of person that takes your bike to the shop for everything, or if you are not REALLY sure how to tune a derailer, leave it on.

JaredMcDonley

I had one on before... did its job and saved me. When all was said and done it was so old (and dried out?) it fractured and feel off. Now I ride without and am very careful...

2manybikes

Maybe we should now move on to discussing the sales potential of a $100 carbon fiber spoke protecter.

Possibly avaliable in Ti as well. For $175 ??

OK OK .....steel is real...........but it's been done...

I think if it's made from hollowtech drilled unobtainium it will weigh less than the air it displaces.
NOW...what about aero? Maybe it's time for some wind tunnel testing. ??

JaredMcDonley

I personally would like to find a better concluding factor for this substance - unobtainium.... Nice!

2manybikes

with sincere aplogies to all, I copied this from a web page.

A Note on Unobtanium

Unobtanium is a super strong material often used in Science Fiction novels. References to it under various names may be found in Spinnerette, Ringworld, and Space Viking.

The super-strength of unobtanium is achieved by strengthening the inter-atomic bonds; these bonds are strengthened using the very strong nuclear force, which is mediated by Bogons. It is well known (see the article in the Scientific American for details) that high temperature superconductivity is mediated by Anyons, which can exist in two space but not three space. Similarly, Bogons can exist in one space but not in 2 or 3 space.

Unobtanium filaments are crystal tubes enclosing a one dimensional space. The effect is achieved by first inducing superconductivity in a planar space and then continuously deforming the crystal plane enclosure into a crystal tube. When one dimensionality is achieved the superconducting current breaks symmetry to split into a gravitational component and a very strong nuclear force component. The very strong nuclear force component strengthens the filament along the longitudital direction and the gravitational component binds the crystalline matrix to the filament.

Unobtanium should not be excessively stressed. When an unobtainum filament is stressed the resistence of the very strong nuclear force component strengthens the gravitational component. If the stress is sufficient the filament collapses into a black hole string which explodes via the Hawking effect.

JaredMcDonley

i dunno about that whole black hole sucking my bike in... kinda sounds like it could suck more than no plastic ring...