MTB Trailcare

Most old trails have issues.  Mongrel's is a difficult blue level trail (as designated by IMBA standards).  It used to have lots of places where loose stones, obstructions, steep grades and eroding features made it a genuine black trail.  Mostly thanks to the sustained effort of one volunteer, Bruce Williamson, Mongrel's is likely to be the first trail authorised by QPWS - that means a new legal trail!  

If you haven't ridden Mongrel's lately, you should.  When you think of this turn and Mongrel's in general, think of Bruce who may be leaving us in the near future to pursue a new future for the family in another place where dirt can be dug.  Replacing Bruce will be one of our great challenges.  He has the work ethic stitched to a logical mind and a very sound understanding of trail building technique.

Following are a series of pics that explain how a new climbing turn was made to ride well in both directions, help the trail last forever and be fun for all riders.  We also hope it explains why all this work is so important.

The QPWS trail audit identified this spot as unsustainable.  You can see how steep the climbing turn is and how erosion has led to a new and widened riding line.

So, first we planned our objectives and then the line best suited to make this turn less steep and more sustainable.  The aim was to raise the entrance and tread on the lower end of the turn and lower the tread into (and out of)  the top entrance while maintaining control over water flow.  

Reducing grade in turns crossing the falline makes sense in some obvious ways:  it is easier to climb, braking ruts are less likely (depending on other building skills) and water that does flow down the trail moves more slowly and is more easily directed away from riding lines.  

The other thing that happens is riders can more easily see and choose their individual line.  Over time that one line, or as we hope here, more than one option will become popular by repetition.  Over time the trail will narrow and flow naturally in both directions.  Expert riders will always find an advanced line off the wall of this turn, but good riders outnumber experts, so it is their riding opinion we want to see written on this turn.

The bypassed trail was 16m long.  The new trail is about 31m.  In essence this means riders have twice the distance to climb (descend) the same corner.  However it is pointless making trail longer if the climbing turn remains steep with falline and drainage issues.  Why bother in the first place? That's one reason we do not like trail widenings.

Having plotted the line, large stones were needed to raise the tread below the corner.  They must remain stable over time.  Timber would not do.  Some of these stones are maybe 140kg+ and were dug (as QPWS require) from within 20m of a fire road and transported on a rock stretcher to the site.  They mostly have shapes suited to the slope of turn and terrain.  These pics make them look like pebbles.

There's a lot to be done here

The wall grows

This is the framework for the lower end of the turn.  On it we added more stone to widen the base of the wall and then lots of very stony soil over the rocks.  The aim was to allow water to seep through to the rocky base rather than pool on the surface of the turn.  You can see the depth of the stone in these pics.

Almost rideable

Before stone and soil were harvested from the top of the turn, a basic line had to be cleared.

From the top entrance and from the fire road waste, ballast was harvested and the first layers were added to the wall.

Compare these photos to those at the end of this trail report to see how much the trail tread was raised after the wall was completed.

The end of day one on this job - time to go home.

 

Day 2: raise the lower tread, reduce the height of the upper tread, build drainages, measure and then close the old trail using refuse from the site.

High points can be built up, or lows can be cut below them.  At the top of this turn, it makes sense to retain high points and dig down for the lows.  Below the turn, rock and soil was added to raise the tread for high points between drains.

Different drains require different approaches.  Above the turn, nicks on a full bench drain through the turn and into more armoured drains below.

Some heavy trail refuse acts as a barrier or dam to heavy water flow.

We measured it.

We closed the old trail.

From above you can see how this trail differs from the original.

This is how the corner turned out:

You can see how different the trail is now compared to earlier photos.  The tread is now a lot higher over the rock wall and not so aggressively bermed.  To match the character of the trail, this is not a high speed corner.

So how does it ride?

Hope you enjoy riding this new turn.