It is sure not my jump. OK, now after some trials I can make this jump.
I think it's one of cynique's jumps, but it also may come from an other person. I have lost the overview.

Trying to catch you Methusalem I just don't have to energy to pop any balloons maybe later..... I'm a little quicker but still not there

I found the jump. It helped me take my time from 27:41 to 21:41.66. Once I firm up the route and make a few changes, I should improve my time even more.

Ah! Just firmed things up a bit more and my time is no 20:24.05! Not anywhere near 17 yet, but I'm working on it.

Keep going, every time round I would improve a little and refine the route a little, to jump or not to jump that is the question

OK, I will have to practice Methusalem's jum a few times before I dast work it into my route. So I will do that before my next attempt. These things are iffy. But with practice.... maybe. There are ever so many places where we have trimmed off space, learned to navigate turns, and learned how to slide down mountain sides. Anything is possible!

I think we all have routes now that we think are better for ourselves, the times on my route where I have to return over already travelled ground is where i look for improvements. I would like to jump up the ledge by the rock tunnel yiu pass after the windmills on left. Quite a bit of time could be cut if I could jump from the rock over the road but I just haven't been able to yet but I did get airborn once. Even then they are not always faster, the new cheat by the ruins field for example, may or may not be faster as I seem to slow down going over cliff. A small thing I have noticed also is that if you hit a balloon not using a pet, try to hit it with your elbow as going over the bump slows you down abit. not much but times 20 could help

And now for some complete different: The step up cheat!
You stop the free ride under the overhang opposite the ruins (on this place the rocks are darker), press "B" and store.
Next start you will reappear on this overhang (the place you normally reach with the right tunnel junction)

Methuselam - I don't know how you find this stuff amazing. Don't see how it could be of much benefit other that shortening the time required to get back to my start point perhaps, but that wouldn't be fair......

In this chase I know it for sure, it was clear pure random.