I am a big guy. Mountains punish me. When I tour, there are a number of things that I take into consideration – but first among them is to keep my route flat, flat, flat.
I do this using Google Maps’ cycling feature. Plot a car route on Google Maps and it tells you how to get from Point A to Point B. Plot a bike route, and it adds an elevation meter. You can then move your route around to reduce the amount of climb – and also make sure that a reasonable day’s climb isn’t all in a single hill!
It’s basically cheating. It’s basically the best thing ever.
But it’s important to know your limits and your wants. Right now, my rule of thumb is <1%, ~.5%, =0%.
Let me explain.
The maximum amount of climb that I will undertake is 5000′ of climb per century. Anything more and I will not be able to get it done. As a rule of thumb, I call it 1 mile of climb spread over 100 miles of riding. That is to say, a 1% average grade.
My ideal day of cycling is a century with a total climb of less than a 2000′. That’s .5mi/100mi, or .5% grade. Magnificent.
A good, if kind of dull, day of cycling, is a century with a total climb of basically zero. One hundred miles of riding, no substantive ups or downs. A flat-out high-speed burn. Not ideal – but not bad!
Here’s an example.
Take a look at the Trans-Am. The first leg (going East to West) will have you start in Yorktown, VA and ends in Murphysboro, IL. The traditional route, as promulgated by Adventure Cycling, is approximately https://goo.gl/maps/gjFs8JXbHM72
That’s 1000 miles of riding, and 30,000′ of climb – AKA, 3000′ per century. That’s more than a .5% grade. Manageable – but not ideal.
Here’s an alternative that starts in Boston: https://goo.gl/maps/G9jNMVd7UUo. It’s 300 miles longer (L>30%) but 10,000′ shallower (E<30%). That, to me, would be a good swap. (I’ve also done the Albany->Buffalo section of this route, and it’s lovely.)
But look at this alternative: https://goo.gl/maps/71LNHjqydrw
The route distance is the same as the above, but with only 6,000 feet of climb. Six thousand feet of climb spread out over almost 1400 miles of riding! Compared to the original that’s L>30%, E<80% – for a total average grade of .07%.
That sounds like my kind of ride.