I have read that in adjusting cup and cone hubs you should leave a small amount of play which will then be taken up by the clamping action of the quick release.

I cannot subscribe to this as each cone is fixed in place by a lock nut and therefore cannot move.

Is this just another old wives tale or is there genuine engineering evidence to support this idea.

I doubt if there is but am willing to listen to those older and/or wiser.

It's true. The quick release is actually able to compress the axle a small amount.

I know this for an absolute fact because of the way I check my bearing adjustment. I clamp a stack of washers to each end of the hub with the quick release, when the wheel is out of the bike. Then, with the skewer closed, I can twirl the axle in my fingers to see if it spins freely but with no play.

The washers don't have to be exactly as thick as the bike's dropouts to simulate the clamping force you get. I simply readjust the skewer to start clamping at the midpoint of its stroke when I change from bike to washers or washers to bike.

Of course, if you have solid, nutted axles without a quick release, you definitely want to take all the play out.

As Garage Sale, yes it's true. There's a bit of axle compression when QRs are closed, but that only applies to QR hubs. Nutted hub axles don't undergo changes when tightened into the bike.

There's a more important consideration. If the dropouts are not perfectly parallel, they'll cause the axle to bow slightly when the hub is installed, possibly binding slightly tight bearings.

In any case, it's difficult to get a perfect cone adjustment off the bike because it's hard to get a good feel when checking for play at the axle. It's easier to detect play at the rim when the wheel is installed, and I'm a fan of those hubs (like Campy) that allow final adjustment while the wheel is installed.

I use what I call the Goldilocks rule when setting hub cones. Checking for play at the rim, if I'm sure there's play, it's too loose, if I'm sure there's zero play it's too tight, and if I think there might be play, but I'm not sure if it's spoke deflection or my imagination, that's just right.

Question is how much is too tight or too loose? you need to snug initially the cones down until they contact the bearings THEN turn back the adjustment 1/4th of a turn; then tighten the locknut fully.

That is a good starting point. Next the adjustment of the QR needs to just begin to feel friction when the lever is at a half way point between closed and opened, then close the QR. Then double check the play as FBinNY discusses. 99% of the time if you adjust the hub as described you will need no further adjustment. There should be no play when the skewer is closed.

Just a note but one of personal preference, I close the skewer toward the seat stay so the clamp is right beside the stay so I can use the stay for leverage. BUT some guys I know point the skewer toward the rear of the bike because they don't want something accidentally snagging the lever and popping it open. I've never had that happen in over 40 years of riding but one never knows I guess.

Every threaded item has a different amount of clearance but I have never worked on a hub that required 1/4 turn. I usually back off one or two spokes on a 36 spoke wheel which would be 1/36or 1/18, I guess. Fine adjustments are usually required but that's all.

If you don't lock the locknut to the cone super tight, some say it's safe to take up excessive clearance by simply putting a wrench on each locknut and tightening without loosening up the locknut, or take out excessive tightness by putting a cone wrench on each cone. There's a lot of friction. Go slow, if the locknuts are too tight you will wind up screwing up the axle threads-so if it won't go, don't force it-loosen the locknut and then readjust.

You don't need to ask about this - just go try it. Bazillions of cup-and-cone quick-release hubs are on bikes all over the world and have been for decades. Did you really think this was an old wive's tale?

You know what man, don't take my word for what I said of anyone else's word, instead go here and make your own determination:

https://www.parktool.com/repair/readhowto.asp?id=105