on2wheelsks

Mine broke loose from the spokes last and since the tabs were broken off, I just cut it off to keep it from making noise. Should I get one back on it soon, or is it just not that big a deal?
TIA
Pat

TallRider

it's not at all important, until your chain hops beyond the cassette and chews your spokes. I've had this happen on two bikes that I'm quite sure were well-adjusted. In one case a friend was riding the bike and may have been cross-chaining. But it's a nearly weightless protection against wheel damage, dorky or not.

dbg

So it is sometimes referred to as a "dork disc" and shouldn't be needed if the rear derailer is properly configured.

BUT, last summer on a bike trip with a big group of experienced riders there was some minor needling to someone about the dork disc on his new bike. That night he removed it and the next morning the chain promptly fell off to the inside of his cassette.

Make sure the limit screw is properly adjusted.

TallRider

nobody ever needs it until they do. and many bikes that idealistically/theoretically shouldn't drop their chain onto the spokes (i.e., limit screw is properly adjusted), still do at some point.

cny-bikeman

It is true that it's not necessary and also true that its absence can lead to expensive repairs. Rear derailleurs do not come out of adjustment, but people sometimes overlook the effect of changing wheels, or don't properly adjust a new derailleur or don't sufficiently inspect the derailleur after a fall (even when you are not on the bike).

onespeedbiker

There is another poster https://www.bikeforums.net/showthread...-through-wheel that had to lay his bike down on the derailleur side and when he subsequently rode the bike, the derailleur went through the wheel and broke 4 spokes; the bike will likely need a new wheel, a new derailleur and hopefully the derailleur can be straightened. I would say if you have to ask if a spoke protector is necessary than I would install a new one until you feel competent that you can keep the derailleur out of the spokes..

Steve530

OTOH, I was riding with a guy on a brand new Fuji when the disc somehow got caught in the chain causing the Ultegra rear derailleur parallel plates to snap completely. Not good.

cny-bikeman

Not sure how that is OTOH, as the disc does not jump out and grab the chain. The fault was not likely that of the disc.

davidad

The dorks ride without one.

stilltooslow

I've been road racing and riding hard for nearly 40 years, and never once had the chain fall beyond the big cog. Granted, I was a bike mechanic and still keep my rides in perfect tune, but if you're the least bit skilled in maintenance and give your bike some occasional attention there should never be an issue. Needless to say, I've never ridden a bike with a dork disc and never will.

Left it on my kid's bike though.....

Jeff Wills

I've got about 40 years of riding, too, but I had a rear derailleur shift the chain into the spokes. That derailleur was on its third bike and maybe had 15,000 miles on it, for the pivots were worn to the point that it allowed the chain to overshift even with properly adjusted limit screws.

None of my bikes have spoke protectors, though. Livin' on the edge, that's me!

zandoval 

So that's what its called...

Turtle Speed

IMO, leave the pie plate on. It's entirely possible to have your derailer hanger bent without you realizing it, whether it's a rough spot on a trail or just when your commuter is sitting around locked up and some drunk idiot bonks into it. Maybe a friend borrows your bike and lays it down on the right side. Could be anything.

Plastic dork disks weigh nothing. Who cares what someone thinks about how it looks? Substance over style.

Medic Zero

Does anyone sell reproductions of the old metal ones?

TallRider

You mean metal ones designed for cassette hubs? I haven't heard of anything like this but it wouldn't surprise me.
I have some (original/old) metal ones for freewheels in my parts bin, and I assume parts bins across the country are similarly stocked.

Steve530

I didn't see it happen, but I'm pretty sure you're right.

It was the first ride, so I suspect the most likely cause was that the derailleur was not properly adjusted and over-shifted. That said, the derailleur body sheared, not the pivots. The wheel was not damaged. The disc was damaged.

Maybe the disc served it's intended purpose.

StanSeven

No you don't need one. Just look at any decent bike on the road and you never see them. Just make sure your bike is set up properly and you'll never have to worry again.

aljohn

Just have two huge dork discs fitted, one each side of the wheel. This will protect the wheel, and look really cool if you write Sky Carbon Disc on it

OldsCOOL

Then I am gladly a dork.

Kimmo

Oops, forgot to fit a spoke protector.

wrk101

You never need it, until you need it. At that point, its too late. I used to remove them from all of my bikes. Recently, I have stopped taking them off.

+1 Even the best adjusted RD, slightly tweak the hanger, and everything changes.

TallRider

I am now a proud dork on all my multi-gear bikes (still no need on a singlespeed). only bike it happened to me on, was my commuter (with a 7-speed claw-attached rear derailer, which I suppose isn't the most precise shifting mechanism anyway). But searching out butted spokes for 27" wheels is a PITA.
It also happened on another (much nicer) bike when I'd lent it to a friend kinda mistreated it (returned it with rusted-out chain, loose spoke, and a couple of other rear spokes that needed to be replaced). But still would have saved me some trouble in that case.