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A few weeks ago, the derailer on my touring bike caught on the chain and ripped itself off the frame. (See the link below for more info on the incident.) The spoke protector was cracked in half by this, which says to me that it did its job: stopping the derailer and chain from damaging the spokes. (The wheel was out of alignment and needed truing, but it still rotated.)

In the future, these "dork discs" or "pie plates" (as some like to call them) are going on all my bikes. My question: Aside from looks and the weight, is there any downside to having one of these on a bike?

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  • Short answer: No. – dee-see Nov 24 '10 at 12:07
  • Yeah. You've answered your question. People remove them because they look cheap and because they weigh a few grams (oohhh!). I agree with you that they do serve a purpose. The answerer below correctly suggests, though, that frequent maintenance will make a pie plate generally unnecessary. – DC_CARR Nov 24 '10 at 17:02
  • @DC_CARR - That's what I was hoping, certainly! (They actually make metal ones that look pretty awesome.) It would be nice if someone made a spoke protector that you could install without removing the cluster, though. – Goodbye Stack Exchange Nov 24 '10 at 18:44
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Apart from looks no, but the pie plate won't necessarily protect against what likely happened.

Pie plates are to keep badly adjusted derailleurs out of the spokes. Obviously, maintaining your bike and keeping the limit screws in place will prevent that from happening.

A stick or squirrel or something caught in your drive train won't necessarily be prevented by the pie plate, because that's not what they are there for.

Unless you regularly smash into things.

I remove the pie plates from all my wheels.

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    Thanks, but this doesn't answer the question. The spoke protector obviously worked in this case. – Goodbye Stack Exchange Nov 24 '10 at 15:21
  • I said apart from looks no. But then I commented that they won't make your wheels impervious. – whatsisname Nov 24 '10 at 15:53
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    I agree that good maintenance usually makes these plates unnecessary. From there, it's just a rider's call as to how likely it is that the derailleur will suddenly go out of alignnment and send the chain into the wheel. When I build a wheel, I do not install a pie plate. When I get a new wheel, though, I do not remove one if it is in place. – DC_CARR Nov 24 '10 at 17:05
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One downside is the deterioration with age. Most of the spoke protectors from the late 80s onwards start as or frosted clear stiff plastic with a lot of flex.

Over time they harden and embrittle, from atmospheric and UV exposure. The disk still does its job but has lost flexibility. So the edges tend to crack and chip. In more extreme cases, the disk can split and cause friction between the inside of the cassette's large cog and the hub and spokes.

ANSWER Plastic spoke protectors look ugly as they get older.

The metal spoke protectors available on some 70s and earlier 80s bikes tend to be a thin piece of steel or perhaps aluminium, which is robust but adds weight. These also tend to be physically large and are highly visible given they're not transparent. These can contribute to windage too, which is not ideal in side winds.


A well-adjusted bike doesn't need spoke protectors, but the two times I would have benefited from them were on significant climbs, where (I think) frame flex allowed the mech to go a little bit further than normal. That's hard to test for on the flat or in the garage.

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