The cache is NOT at the listed coordinates, although that is the nearest free public car park. The cache is pedestrian access only. Please park with consideration. This is NOT a cache and dash.
Instructions for experienced puzzle cachers
Go to location by track.
Take gps reading in a flash.
Use your reading to fill in the missing coordinates in this formula: N52° ??.?05' W002° ??.?25'
Short walk to new coordinates.
Retrieve cache from bikes. 
Step by step instructions for non-puzzle cachers
First decode the rot-13 instructions below, possibly by using a website like this: http://www.rot13.com
Ybbx ng gur uvag sbe gur chmmyr naq vs gung qbrfa'g uryc gura gel tbbtyvat vg.
Hfr gur jro-onfrq znc gbby fhttrfgrq ol ze tbbtyr gb svaq gur ybpngvba bs ovxrf.synfu.genpx
Tb gb gung culfvpny ybpngvba.
Take a gps reading.
Use your reading to fill in the missing digits in these coordinates: N52° ??.?05' W002° ??.?25'
Short walk to new coordinates.
Retrieve cache from bikes.