As an avid cyclist for nearly 16 years, and working in the start-up world as a team member or starting my own business, for the last 12 years, I've often thought about this connection, and why cycling is so popular in Silicon Valley (though I don't live there, I've biked there).
It's great to hear the perspective of someone with a business background and new to cycling.
Though I disagree with the challenges point. I find that in cycling, you look at a peak and think "i'll never make it up there", but then put in the effort, and before you know it, you're at the top.
I've dreaded developing certain features, thinking that the task would take forever, and then, in a few hours, it's done. I've also had the experience where you think something will be simple, and it takes days or even weeks to get through it.
The 'gears to conserve energy' point is interesting too. I ride a single speed mountain bike and live in the Coast Mountains. I don't have the luxury of conserving energy on a climb. You gotta give it all you got, and keep your momentum.
Similar to how I look at start-ups.