You have to admit, when it comes to riding bikes — the kind powered by your legs — the phrase “80 percent downhill" has a pretty great ring to it.

That’s how the inimitable Map Guy talked me into postponing a planned canoe paddle and instead loading our mountain bikes and heading toward the hills for a loooong ride that Map Guy assured me would be “80 percent downhill."

The plan, such as it was: We’d caravan up in our two vehicles, park his truck at Lava Lake, then shuttle ourselves and our bikes in my van the 17-or-so miles back uphill and park near Mount Bachelor, where we’d climb on our bikes and ride a sliver of singletrack through the forest to the Metolius-Windigo Trail.

We parked on the shoulder close to the Nordic Center and picked up the path a little ways from the trailhead. An even easier option is taking the left-curving road as you enter West Village parking area and parking on the dirt road on the right-hand side, where you’ll also find the trailhead.

Still another option: Parking across the highway at the Dutchman Flat parking area at the base of Tumalo Mountain, then carefully crossing the highway and picking up the trail from that dirt road.

As we unloaded, Map Guy began expressing concern over whether or not I’d brought a helmet, given some of the steep and rocky terrain we’d encounter. I had, but told him with a flippant shrug that I hadn’t. Sometimes it’s more fun letting people twist in the wind than to level with them. After letting him scold me for a minute or two, I unhooked my helmet from my bike’s handlebars and clipped it on.

Once again, Map Guy’s name proved ironic as we set out in search of the trail. We headed down the hill to the right of the Nordic Center building, on the wide, mulchy dirt road that serves as entry into the complex, and I was struck by how ugly and chewed up the ground here is when not covered in snow. In just a few minutes’ time, Map Guy spotted the trail we wanted, singletrack branching off toward the right, close to Century Drive.

This is the Bachelor Tie, which we took mostly downhill about two miles to the Metolius-Windigo Trail where the two connect near Todd Creek Horse Camp (another parking option in summer, but the gate to the camp is already closed, according to Deschutes National Forest).

We bore left on the Metolius-Windigo toward Sparks Lake, pausing here and there for stunning, up-close views of Mount Bachelor’s west-facing side. The Deschutes National Forest here ranges from dense to not-so-dense.

From the Hosmer Lake area, we continued another five miles south to Lava Lake, enjoying riding by a meadow here, a lava flow there. Anyone who uses the Metolius-Windigo trail should give thanks and credit to the equestrian groups — its primary users, according to Deschutes National Forest Trails Specialist Chris Sabo — who take fantastic care of the trail. The only time we encountered a tree across the trail was along the eastern shore of Lava Lake.

Truth be told I’m mostly a pavement-pushing bicycle commuter, so pity poor Map Guy, who insisted on riding behind me. I tend to barge up the hills, but, at first, took it pretty gingerly around the technical sections, which means I slammed on my brakes and would try to walk my bike over or around them.

Map Guy, on the other hand, is a trooper who rolls bravely over any and all lava rocks and roots. This means I’d repeatedly get ahead of him on a hill — to be sure, that “80 percent downhill" estimate is generous; I’d put it more at 70 percent — and then he’d catch up to me whenever I came to a rock larger than a grapefruit.

It’s early in the season yet, and we encountered sections of loose sand that will firm up once a little rainfall or, gulp, snow sets in.

Somewhere between Sparks and Hosmer lakes, though, something clicked for me: I realized that, much like Map Guy’s, my bike would also roll right over a lot of the rocky sections I’d been going around or stepping over.

For shaving a lot of time off our ride, this was a great development. I began letting up on the brakes and zooming down some of the hills, even shifting gears and pedaling down some of them. Map Guy called me “grasshopper" and complimented me a few times, which, trust me, never happens. Map Guy and I have a very antagonistic friendship, so I felt something like a neglected toddler being hugged for the first time.

But there are drawbacks to newfound overconfidence, especially pedaling over loose sand. After trundling over some rocks, I began picking up speed through a flat section when, as I was heading into a turn, sand grabbed my wheel and took it one way, while my upper body went another.

Fortunately, I was in loose gravel and no trees or lava rock were around to break my fall or my face. Sometimes, the measure of a good outing is what you’ve lost: In this case, I lost my fear of riding over obstacles, but also the sunglasses I’d hooked on my shirt. Further into the ride I noticed they’d disappeared, probably when I took a spill. Map Guy also did a face plant when he tried to ride, starting from a standstill, off a rocky one-foot drop. The only thing hurt was his ego.

For those wanting a similar but shorter ride than what we took, another option is parking at Sparks Lake off Forest Road 400, which makes for “just" a 10-mile ride one way to Lava Lake. You could then ride back on the trail, or take the shoulder of the highway.

As it was, according to my trusty Garmin watch’s GPS gizmo, we pedaled (and coasted!) about 14 miles, maybe a little farther because I occasionally forgot to restart it a few times after I stopped to snap photos.

Map Guy remarked something along the lines of the ride being just long enough that, by the time you get to Lava Lake, you’re pretty much sick of it. However, for those to whom such words are heresy, Sabo says that for more punishment, you can also catch the roughly 10-mile Edison-Lava Trail to Edison Sno-park.

Sabo also urges mountain bike riders to be aware of, and courteous to, equestrians, whose horses won’t necessarily recognize the sometimes strangely dressed cyclists sharing the trail with them. Talking to the riders can help put their horses at ease.

“It really can spook some horses if they don’t hear a biker coming, or if they’re not well-trail-trained," he said.

It’s all