Hi, 

I’m new here and was hoping to get a little help. 
I have a new-to-me 101 and the front brake cable outer is too short so I bought a new front cable set. I received it and now the problem is the end that goes to the brake lever is way too big to fit. Because I’m new to these particular bikes I can’t tell if my brake lever is incorrect or if the cable I just bought is incorrect. The cable is listed as fitting 1928-1931+. Any ideas? Where do you get your cables from?

In the photo where I’m holding the two ends, the new cable is on the left and the old one is on the right. 

Jordan, have you considered re-shaping your cable end with a file or Dremel (wearing a mask, likely to contain lead)?  Or as Tim suggests find an end that will fit, snip off the too big end, and solder on one that'll fit.

It may be that the thicker nipple you have there is better suited at the lower swivel....

Take really really care when fitting those nipples, be asure a good solid back looped wire knot is at the head or the wire could slip through in an emergency brake. Been there, done that! A bit fiddly bend and back loop a few enough strands and may prick your fingers but with a needle nose plier and a bit of hammer...The solder only is not enough to hold the wire. I never again trust a regular mandrel spred in those nipples.  

And don't use excessive heat (glowing the wire) or that will weaken the wire strands. I also use proper acid as flux and neutrilize that thouroghly with baking soda afterwards.

Bowden wires do give, so a thick gauge wire is better than a thin, original is thin and a thicker wire makes better brake response...