I'm a beginner bike mechanic and am working on a used project bike I got cheap. I was just switching out the rear tire and tube for some new 700x25c Gatorskins and when I went to go put the wheel back, I found a really perplexing issue that I hadn't noticed. Namely, the derailleur side of the rear hub had this very strange offset to it, while the opposite hub had no offset.
When I went to put the wheel back on, I struggled with putting the derailleur side hub in, and with getting the right alignment on the non-offset hub.
This is the first time I've encountered this type of derailleur and I'm not sure what to do. Is it possible to get an offset of the same length, on the other side? Any advice?