The heavy section is for the well trained gravel rider. Technically these are just medium tracks but much longer and more climbing in total, though some parts might contain some downhills that require a bit more skilled rider and can sometimes be very rocky roads. But I ride them my self with my Kona Rove NRB DL with 47mm tires and my girlfriend rides with 42mm tires.
Some routes have warnings in the description, please don’t take them lightly and be prepared.
98km 1200hm
94km - 1200hm
Fixed Gear Goes Gravel - by Gabrie
This route was specially created for Fixed Gear Coffee in Valkenburg
85KM - 1000HM
82km - 1200hm