Rear drop out - is this ok?
 

Looking at a used bike and noticed this screw in the rear dropout. Is this jerry-rigged? Should I be concerned? Thanks in advance...

https://cimg8.ibsrv.net/gimg/bikefor...5c8eaa4222.jpg

Uh oh, looks like someone mighta been adjusting your dropout.

Totally normal. Lots of mid and lower range bikes left the factory with those dropout spacers.

Looks like one of these to limit axle placement.
https://cimg7.ibsrv.net/gimg/bikefor...3fd623ee24.jpg

That may have been done because the original screw is still in place but broken off. What you see is similar to what was used on thousands of mid-range bikes over the bike boom years. It works just fine as long as you are OK with where the wheel sits in relationship to the cassette cogs and the rear derailleur. And you can improve the location by filing some more or getting a new washer and filing it less.

If this is a flip, it matters. If this is a rider and you can overlook it, it will work for you the next decade. Then spend $1.50 for new screw, washer and nut, do 10 minutes of work and go the next decade. Better steel, $3 and nicely greased - 2 decades.

Edit: or go to your coop and rummage around and find one of those parts shown above. The right bike shop might even have a new one.

With that piece, your hub is currently positioned perfectly for optimum indexed shifting.

Thanks, all! You've answered my question... Seems normal! I'd never seen one of those before.

Well, not really as those kind of spacers predated index shifting by many years. The stops are more like poor man’s horizontal adjuster screws. It allows for shorter wheelbase, although I’ve never seen anyone actually adjust the wheel base with an adjuster screw. For most bikes, the adjuster screw is just kind of “there”.

While they may pre-date indexing, the fact is that the wheel is perfectly positioned for optimum indexed shifting--with the sprockets as close to the jockey wheel as practicable.

I really doubt that there would be any significant difference in indexing (if that bike has indexing) if the stops were removed and the wheel moved rearward.

Modern vertical dropouts push the axle significantly forward of the derailer as can be seen in these examples.

https://cimg6.ibsrv.net/gimg/bikefor...21320f42f.jpeg

https://cimg9.ibsrv.net/gimg/bikefor...aedae196a.jpeg


https://cimg6.ibsrv.net/gimg/bikefor...046240638.jpeg

Those came standard on many bikes, not just the lower end ones. Often used as the NDS counterpart of a separate derailleur hanger, of just instead of dropout adjuster screws.

My Peugeot PR10 came with them:

https://cimg9.ibsrv.net/gimg/bikefor...e2bb19c5c6.jpg

Here is Shimano's 2005 spec for the recommended placement of axle relative to RD location. For SIS shifting bikes.

OP's pic seems to be reasonably close.

https://cimg8.ibsrv.net/gimg/bikefor...6aa66298a1.jpg

The first one I've seen on a short dropout.