Mountain biking skills usually grow proportionally with leg power. So if a slope requires more skill than you have to descend it safely, you will usually not even have the strength to climb it with a normal mountain bike. An electrical bike is dangerous for amateurs precisely because it decreases the strength needed to climb, but not the skill needed to safely ride down the slope.
While I’m typically very much against using hourly rates to make proposals or communicate with clients in any way, I still use them at regular intervals myself.
Here is why: Just like e-bikes, hourly rates make comparisons between otherwise very different offers very easy to do. So easy in fact, that it enables clients to feel like they can easily decide between totally different options, even though they actually lack the knowledge to really take everything important into consideration.
You however do understand enough about your work to make meaningful comparisons, so there’s no danger in you calculating the realistic internal per-hour rate that you earn for each type of project or product you offer.
If you do that, if you calculate the approximate per-hour rate you earn on each of your different offers and projects, you will be able to fairly compare them. This will enable you to choose the ones you really want or need more of, and which ones should be only offered in special circumstances.