If you are not getting paid to ride your bike with all of the accompanying restrictions/requirements that it entails why would you remove either or both?
I have done a bit of online and LBS research and both sources appear to be in agreement that both items have the potential to serve a useful purpose.
Manufacturers continue to put them on the bikes they build.
What gives?
Is it simply a weird culture thing and a huge % of wannabe racers do it for no other reason than copying what the pros do? Or do most just do it because they think they are supposed to?
To each his own but that would be too akin to the Sunday morning high arc softball player using a $500 alloy bat while wearing eye black imo.
Or did everyone that does it simply eye up their bike one day and say "these 2 things are ugly" and remove them?
Lastly, do reflectors fall in the same category?

I don't use caps because that's just another thing to unthread and lose on the side of the road. On a bike, stem caps are superfluous, unless you have like LED flashing acrylic dice or something. That's cool.
I removed the dork disc when I changed out my cassette, because it's as superfluous as valve caps. If the RD is adjusted correctly, that disc will never do anything except get destroyed by the sun and clang around on your rear wheel.
I didn't need to remove the reflectors because the bike only came with two, and they weren't even installed. I do run a blinky front light and a 2W taillight at all times. Reflectors do indeed serve a purpose, but I ride in daylight hours, so they won't help me.

Weird?

Partly style points, and partly practicality and beauty.

Spoke protector disks age poorly. Plastic gets discovered. The things crack. The look is cleaner without them, so I take the risk.

They used to be metal. Some of the older metal ones look nice, IMHO. Maybe someone should put out a line of spoke protectors in anodized colors.

Valve caps. Yes on Schrader. No on presta. They are redundant on presta and strip easily, so I don't bother.

Mainly I just run with what I feel looks good and is convenient. No big deal either way.

None of my wheels came with discs.

What is the purpose of valve caps? I keep them on when I fold up tubes to keep the end of the stem from rubbing a hole in the tube. I leave them off of mounted tubes because I check the tires several times a week and don't want to bother with putting them on and off.

I always remove the dork disc simply because it's going to yellow and look nasty over time. I remove all reflectors so I can be a stealth riding cycling ninja at night. However, I do leave the valve caps on. After seeing this thread I may remove them for extra poseur points.

I keep valve caps on. The main reason is that when I puncture I put my spare tube on and roll up the punctured one to fix later. The cap protects the tube from getting another hole.

Yeah, this would work with just a cap on the spare, but it's easier to have a cap on each valve.

They protect from grime getting into the valve, maybe protect it from getting bent in a fall?

And honestly I think they look cool and complete the valve...

I'd save more weight by cutting my hair

I'm not fast enough to worry about how much those valve caps weigh.

I can see the point about removing the dork disc. My old bike's disc had yellowed and made the bike look bad, and that was a Walmart bike.

Valve caps are just another thing to come loose and lose to me, never had a problem not using them.

Dork discs I just think look silly, and you'll never need one if your rear derailleur is adjusted properly.

Let us not forget those little presta nuts that hold the valves onto the rims.

Used to use those for completeness until one day when I got sick and tired of fiddling w/them.

I use valve caps until I lose them which is always.

Look how ugly this dork disc is. Hence why they get removed..........

I take the disc off when it breaks or gets ugly...I use the valve caps until I lose them. I do not pay any attention to what others do.

None of my current bikes (5) had come with a spoke protector (aka - "dork disc"). The last bike I bought with a spoke protector was in 1985, paid $300. I removed it when I changed out the cassette.

Not needed if the rear derailleur limit screws are adjusted properly. But, sure, there is some risk of chain diving into spokes. Has never happened to me. Well....as a kid, sure, the chain smashed into the rear spokes; but back then I would stop the bike by jamming my foot between seat tube and rear wheel.

As for valve caps - for schrader they are definitely needed. For presta, not really. But I keep them on, especially for my mtb bike, as some protection against damaged to the valve from rocks.

<shrug>

I use lighted flashing valve caps, because I bike commute in Seattle year round, and if you do that in winter you are going to be in the dark both ways, and valve cap lights can be seen from the side easily, especially at speed when they make a sort of lighted circle out of each wheel. There are spoke reflectors and spoke mounted lights available, but the valve cap lights are less bulky that the crescent shaped ones and last much longer than the small round ones.

Almost all my bikes have IGH, and since there is no derailleur on those, there is no point to a dork disc.

Valve caps I keep on. I don't know why I just do. I took the wheel reflectors off my current road bike because they were the largest ugliest things I've ever seen. Dork disk gets removed for the already stated reasons.

I think there is a potential market, if someone has already come up with this idea, for a carbon fiber dork disk. Just rename it the aero spoke protection system and claim it increases aerodynamic efficiency by .002%.

Really?!

Are they currently being made?

I still have my dork disk and valve caps on. Causes those riders on their cheater carbon bikes a good seethe when I fly past them (or so I tell myself).

Sounds like I better get to work on my Kickstarter webpage.

Agree. I remove them and keep them stored away safely at home.

In my experience, the RD hitting spokes or dropping the chain into the spokes is most often caused by a bent hanger as a result of a crash, the bike falling over or other mishandling rather than missadjustment, though the latter is certainly possible.

How about the fact that valve caps keep dirt and mud out of the valve stem. This is especially true for mountain bikes and gravel grinders.

For My Touring bike , I have different priorities ..

There's no reason to have a dork disk if your rear derailleur is properly aligned.
Removing the valve cap before inflating your tires is a pain...you do check and inflate your tires to proper psi before riding, don't you?

Do you leave the tags on all of your clothes? The manufacturers put them there, why bother taking them off?

Huh?
i Ofc take the price tag off my clothes and any other items I purchase for that matter.
What are you trying to say? Do you also cut off the stitched on tags? Wow...

As for tire pressure, I now check it weekly and inflate as needed. I know most people check it daily but I am not racing and so far it has never gotten near the point of me worrying about a pinch flat. Even when I made the mistake of not checking it for a month after I first started riding again lol.

I am am curious though. Assuming you drive a car do you check the tire pressure on your car tires daily?
I am not positive but I believe that tire manufactures would suggest that.

My Cannondale I got in January didn't even have valve covers. I still have "dork disk" but this off season when I nothing better to do I will remove it because its UGLY! My LGS doesn't put the wheel reflectors on, he asks if you want them or not when you buy a bike. Does look better but in the end I don't really care if they are there or not.