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Trailbuilding Basics

Chapter 6 - Glossary

Back-cut - The vertical part of the bench cut that is blended into the backslope.

Backslope - Slope on the uphill side of the trail. This should be a gradual change from the tread, preventing a waterfall effect when runoff flows off the uphill side onto the tread. Helps slow the water.

Bench cut - Creating a semi-flat trail tread where there wasn't one before by digging into the hill side, down to mineral soil. Care must be taken when cutting into hillsides to preserve some outslope while making a ridable path.

Berm - The ridge that develops on the dowhill side of a trail. It is caused by tread compaction and soil displacement by trail users. A berm will cause water to be trapped on the trail.

Bridges - Used to transport trail users over obstacles like ravines, bogs, creeks, or rivers.

Climbing turn - A turn that climbs (or descends) the existing grade of a hill, as it makes the transition from the upper leg to the lower leg.

Clinometer - Device used to measure the slope of the land.

Control points - Points of interest that trail users will be attracted to or should avoid. These should be marked and used to create the trail. Types include geographic, historic, or boundaries.

Cribwall - A wall that is built up to raise the trail significantly. Can be built with rock or wood.

Deberming - Removing the ridge of dirt that forms on the downhill side of the trail, preventing water from flowing across the trail. See "outsloping" and "berm."

Directional use trail - A trail that users are intended to travel in one direction.

Drainage - Getting water off the trail.

Exceeding the fall of the hill - If a trail is built on more than half of the existing hillside slope, gravity will pull water down the trail instead of across.

Fall line - Direction water flows down hill (path of least resistance). A trail that runs on the fall line will cause water to run down the trail.

Fillslope - When dirt that is excavated during the bench cut is used to create half or more of the tread. Fillslope should not be used in a bench cut as it will not compact as well as mineral soil.

IMBA - International Mountain Bicycling Association, PO Box 7578, Boulder, CO, USA 80306, 303-545-9011, - Great help on trail design, construction, maintenance and management information.

Land Manager - Any person that makes decisions regarding land use.

Mineral soil - Soil that is below the top layer of leaves, roots, and organic material. When digging in a new bench cut always dig down to the mineral soil.

Multiple use trails - Trails that are built for more than one possible user. For example: hikers, bikers and equestrians on one trail.

Open and flowing - A type of design that allows for sweeping turns, higher speeds, and better sight lines.

Outslope - Trail tread should slope slightly downhill so water runs off the trail, rather then being trapped and running on the trail.

Percent of grade - The method of measuring how steep a trail or slope is. (10 percent = a rise or fall of 10 feet per 100 linear feet of trail.)

Rolling grade dip - Non-obtrusive drainage device that shunts water off the side of a hill by altering the grade of the trail.

Single use trails - Trails that are designed and built for only one intended user. This can be problematic if future use may include other types of use.

Slope - The natural (or created) shape of the land. What is shown on contour maps. The term is generally used to refer to the hill, not the trail.

Social trails - Trails created by recreationalists as they wander from the "official" trail.

Subaru - Great car! Ask for the heated seats.

Switchbacks - A switchback is a level structure that the trail is routed into, makes a transition (turn), then is routed out in the opposite direction.

Texturing - The act of placing natural features (rocks, logs) back into a trail to help control speed or user conflict.

Tight and technical - A type of design that allows for tight turns, slow speeds, and can take fuller advantage of natural technical features.

Topo map - Map that charts elevation changes and shows features such as knolls, ravines, rivers, and contours.

Trail Care Crews - IMBA's "Johnny Appleseed" approach to spreading knowledge on trail design, construction and maintenance.

Trail corridor - Area three feet on either side of tread. Corridor should be cleared of fast-growing impediments, but grasses and trees should be left in or encouraged.

Tread - Clear ground on which trail users travel. Grass, bare dirt, roots and rocks may be part of the tread. The tread width varies depending on the type of trail or users.

Tread creep - When a trail sags or slides down the side of the hill. Usually caused by roots on the downhill side of a tree or an improper bench cut.

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