Anatomy of a Trail - Building and Maintaining Features with Tricia Davis, DPT and Natalie Narburgh

Fri 9/23 Cranksisters WorkshopCranksisters held Crankfest at Kanuga this past weekend and what a fun gathering for the female identifying folks. It included this and many other workshops, clinics, racing, group rides, food, drinks and even an 80’s dance party! Pisgah Area SORBA was there with some Cognitive swag for the ladies, info on joining and donating, as well as a workshop on the Anatomy of Trail Features. We thought we would summarize the workshop and make it available to all, so read on if you’d like to learn more about trail anatomy and maintenance! Water=Trail Kryptonite:The main objective when building and maintaining trails is to limit EROSION from the millions of gallons of water that fall from the skies over Pisgah each year. Water must be diverted off the tread surface (where we ride) of the trails in order to limit erosion. If water diverts too quickly, it forms gullies and ditches and can really do a number on the trail. If water doesn’t get off the trails quickly enough, puddles and bogs can form which soften the tread, create mud, and encourage users to go around it, widening the trails. This is also known as trail creep. Water can destroy trails quickly if not managed with good building or maintenance.Preserving a trails' tread surface and giving water a place to go will minimize the time required by our volunteers and help preserve resources for our non-profit. We all know there are no trail fairies. It’s hard work that keeps our trails flowing.Think Like Water:Just like mountain bikers, water loves to FLOW. We need to look at the trail and think about where all the water will go. A good way to know for sure is to get out in the rain and hike (so long as it’s not too muddy) to see where water is coming from and where it is going. Then, we can get a plan together to allow the water to flow off the trail at an appropriate speed with the following trail features. These features are the parts of a trail’s ANATOMY that allow it to survive the deluge of rain that Pisgah delivers. Think of the OUTSLOPE, DRAINS and ROLLING GRADE DIPS as the heart, lungs and brains of the trail! It is these features that keep our beloved Pisgah Trails alive.Outslope:The side cut or bench of a trail should be angled 2-5% to allow water to sheet slowly off a trail and move down the slope and off trail. With proper outslope water does not stand a chance of staying on the tread surface and picking up momentum to run straight down the trail. This allows the water and the rider to go along it’s merry way without messing each other up and everyone wins!Outslope is maintained with tools that dig the outside “berm” off the trail to keep the downward flow of water and ensure the tread surface doesn’t get cupped or form a gully.Trails should be built with outslope along the side of a hill preferably and kept off fall lines. Unfortunately, some of Pisgah’s legacy trails have long sections that run straight down fall lines, and although these are super fun to ride (until they’re not) they are all but impossible to maintain. Locust steps, rock armoring and re-routes can help, but are expensive, time consuming and not the best use of limited resources.Drains/Knicks:These little gems are large semi-circular areas that slope downward and off the trail that - you guessed it- allow water to drain from the trails. They are used frequently to allow water to flow when outslope is difficult to achieve based on where a trail is place and how steep it is. Good drains are wide, clear and blend into the natural terrain. They just sit there and do their job, not really asking much from users except to be cleaned out from time to time.If these drains become plugged up silt, debris, leaves and sticks can all accumulate and back the water up on the trail. As a clogged drain in your house can be, it can also devastate a trail to have a drain plugged up for too long. Best practice is to use a flat head shovel, hoe or McLeod and pull the debris out, scattering it wide and away from other drains and the trail. This is where I spend 90% of my time as a Trail Crew Leader (TCL) and volunteer in the forest and believe me it is hard work.Rolling Grade Dips:These drainage features are really what bring the smiles and flow (not just for riders, but also for the rider) to the trails. Taking advantage of small elevation changes with areas to allow water to slow down (ramp up) and get off the trail (ramp down and off) RGD’s are the real BRAINS of sustainable trail anatomy. Like riding a rollercoaster RGD’s can give the sensation of FLOW on the bike while keeping water off the trail and erosion at bay.The RGD’s don’t take care of themselves and can degrade over time, with water, dragging brakes and other erosive forces. Keeping the rolling part built up to slow water and the dip part (the knick or drain) clear takes maintenance and volunteer time to keep the trails rolling well.Come on Out/Get Involved:Now that you know a few of the basic anatomy features used in sustainable trail construction and maintenance we encourage you to look for them on your next ride. Come on out and get involved in a maintenance day and help us keep the trails in great shape. Head to the “volunteer” tab on our website to find some upcoming opportunities. If it’s tough to make time to volunteer,  you can also support our work by becoming a member or donating directly to our cause! Lastly, stay up to date and know when the next trail days are by signing up for the newsletter. We hope to see you soon! Pisgah Area SORBA is nonprofit and volunteer based organization dedicated to preserving mountain biking opportunities by maintaining and improving trail systems in the Pisgah Ranger District and surrounding region.