The spring puts pressure on the screw to keep it from backing out. I still think the OPs are backwards because you can see the slot in the head of the screw for adjusting. So the head and spring should be outside the axle slot so the wheel can be centered and both screws tightened. Even the heavy old American bikes of the '50s had rear wheel adjusting screws.

+1 / -1

Yes, the spring serves to keep the screw from moving when nothing is bearing on it. It's an SOP anti-vibration technique that was used, for example on derailleur limit screws, and things like auto carburetor and choke adjustment screws.

The minus one, is that the screws do go head to the wheel to make a solid stop for the axle with the spring tucked within the dropout. They originally came with a small knurled cap nut to both protect the thread and allow adjustment (which should be done with no load).

You wouldn't thread the screw in from the back because repeatedly mounting the wheel against it plain end would risk mushrooming it, and leaving you with a screw that couldn't be removed. That would be poor planning.

The original style are available if the OP wanted to replace the ones which are broken.

Dropout Adjustment Screws

Ok. Issue I'm having is I'd like to set the stop further out. The spring, fully compressed is getting in the way. If that's the purpose, I should be able just to cut the spring shorter, yes?

If you still have the knurled nuts, you can transfer the spring to the back and it'll do the same job. That preserves it so you can move it back later if you wish.

Oh. Does it not matter which side it's on?

No and yes.

The spring functions the same on either side as far ad an anti-vibration device. However, when trapped in the slot by the screw head it can't go anyplace. Behind the dropout, only the removable knurled nut holds it home, so if that nut should work loose, the spring will push it off, then jump off like one of those fake snakes in a can.

I don't see a problem switching it to the back for your purpose, just tweak the nut home a but harder once the wheel is in place to keep the screw from moving. (or use locktite on the nut)

The Campy style use the screw and spring on the inside against the axle with the knurled cap on the outside of the dropout to the rear (put a drop of Loctite 242). Italian bicycles were mostly handmade and rarely very straight, though they rode straight. But the dropout adjuster usually were a little one way or the other different from each other for a straight wheel.

J

Thanks!

It'll be a little awkward if you ever get a bike with these babies:

http://i.ebayimg.com/images/g/vrQAAO...sM/s-l1600.jpg

I often run without the screws at all.

Yeah, that's why I hesitate to completely remove.

My new bike has none. The old roadie though...

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Exactly. Those cap nuts come adrift frequently.