Just some of the Valley Mountain Bikers along with Subaru/IMBA Trail Care Crew leaders Scott and Aaryn.
Contour trail designs can have three basic types of flow: open and flowing, tight and technical, or a hybrid. Understanding flow can reduce erosion, user conflict and accidents. More.
Scott runs a new trail alignment in both directions to test trail flow. Some flow tips: Avoid long, straight lines. Use natural obstacles to accentuate curves and grade reversals. A well-flagged tread resembles a serpentine line with rounded arcs. Optimum flow comes from consistency in the radius of turns.
Two productive days of trail layout and construction resulted in a half-mile of carefully designed and flagged trail and 400 feet of textbook full bench singletrack.
This site was picked for a stream crossing because of its narrowness and stable shorelines. Always check for indications of the high water mark when identifying your bridge site. These may include mud marks on rocks or trees, accumulated debris, and eroding shorelines.
The group constructed this small crib wall to create a relatively flat platform on which to locate a climbing turn. Grade reversals before and after the turn will shed water and slow approaching trail users.

Carving Turns in Pennsylvania's Lehigh Valley with the Subaru/IMBA Trail Care Crew

Scott Linnenburger and Aaryn Kay of the Subaru/IMBA Trail Care Crew were invited to Pennsylvania's Lehigh Valley by the IMBA-affiliated Valley Mountain Bikers (VMB) for planning and construction of new singletrack at Bear Creek Ski Area. The Crew led an IMBA Trailbuilding School, a volunteer trailwork project, and joined VMB members for an exploration of the entire 400-acre Bear Creek property and a number of other local trails.

Located about one hour north of Philadelphia, the Lehigh Valley boasts a diverse trail system and some great mountain biking.

VMB's goal is to improve the Bear Creek trail system which consists mostly of flat, non-technical service roads and historic, eroded fall-line trails. The weekend's work focused on improving trail flow through reroutes, tweaks, and future planning.

Carefully designed flow is vital on trails for cyclists. Mountain bikers love the rhythm of a trail where one turn blends into the next, and every descent leads into another rise. A trail with good flow helps minimize erosion, user conflict, and safety concerns.

Poor trail flow can be often be resolved with careful reroutes. Other creative fixes include adding banking to small radius turns to prevent hard breaking and subsequent tire-induced, braking bumps. Ramps on either side of large rocks within the trail allow both downhill and uphill riders to roll the obstacle, thus maintaining flow in both directions.

The best way to ensure good flow is to design it into new trail layout.

When complete, the Bear Creek system will include an almost 8-mile singletrack that climbs to the top of the ski area. The trail will include expert-only spurs with big rock drops.

Special thanks to VMB President and Eastern PA IMBA Rep Joe Transue for leading the visit. Contact Joe at to volunteer for ongoing Bear Creek trail construction. The sooner this gem is finished, the sooner it can be enjoyed!