How can I make an unsupported inclined rail?

Solution 1:

There's no way to create an incline like that by just placing rails and blocks, but you can use a sticky piston to "lift" the rails up. By pulling up one rail, the sticky piston makes the rail beside it inclined, and the rail it "lifted" breaks, leaving just the inclined rail with no block beside it. You can then remove the sticky piston. You can also use a normal piston to push a rail into the space where the unsupported incline will “aim”, which lifts the adjacent rail up into a slope and breaks the pushed piston, leaving just the unsupported inclined rail.

Either way is the same idea: get a rail into position with a piston so that it encourages the desired angled rail, without a block, so the rail breaks leaving its neighbour raised.

This video demonstrates how the second method works:

The thing to be careful of is that, once the piston has pulled up the rail and created the incline, any blocks that change adjacent to the incline will remind the game to check the rail to see if it's still a legal placement, and it will break. Essentially, anything that causes a block update beside the incline will make it notice that it's not supposed to be inclined and will cause it to break. So if you need to power the "jump" rail, make sure to place your redstone power source before using the sticky piston.