I only had to go 3mi from my hunting ground back then to my shop (butchered everything myself back then), so it didn't have to be very elegant, and I could easily make multiple trips.
The first time I tried it, it took a long time of trial and error before I realized how much cleaning I had to do to get her on the back, and how futile it was to try to get an entire deer on at once. I first tried setting her up like a passenger and lashing her front legs over my shoulders, but after almost dropping my bike (deer have VERY NARROW BUTTS!!!) a few times, I gave up on that. So then I tried cutting her in half, front from back, and having her legs straddle the bike. Still no good, because her head kept flopping to one side and dragging the whole mess down. So I gave up. Quartered, partially boned her out, packed and stacked, wrapped in a tarp, and lashed it down over the passenger seat. Worked out pretty slick at that point.
Then I got home, drenched in sweat, and told the story of my troubles to my uncle, who was also hanging HIS deer in my shop, asked me, "why didn't you just make 2 trips?"
If anyone would have video taped me trying to get that d@mn doe on my bike, America's Funniest Videos would have made them $10,000 richer!