The route starts at the parking lot at the church of Lammersdorf and you follow it clockwise. 61% of the route consists of dirt roads (gravel roads), and you will overcome about 1150 meters of altitude (less than the route you indicate). The route has as its destination the course of the Kall as well as the Rursee and the Urftsee (two reservoirs with gravel roads along the shore).

You first cycle on the wide and very good gravel roads in the forest east of Lammersdorf and descend on these gravel roads to the Kalltalsperre. On gravel roads you follow the reservoir over the north and west banks. Then you will end up on an excellent asphalt road that will take you to the dam, then you will continue down the Kalldal on a gravel road in excellent condition. You briefly cross the L160 and continue down into the Kalldal. At the confluence of the Fringskrafterbach and the Kall, you climb up to the village of Schmidt, initially up to 19% and a partly very stony ground (so it can become slippery when wet).

Partly paved gravel roads lead to Schmidt and then go steeply over asphalt down to the Rursee. You follow this reservoir on the north side towards Heimbach on gravel roads (note: at the end of May 2023, this section was closed with fences due to a collapsed rock face, the fence was a bit open and it was easy to pass, a concrete structure was erected in two places to stop falling debris (you can easily pass here, see photo)). In the tourist season, when the weather is nice, there can be quite a few hikers and cyclists here.

Via the Schwammenauel dam you change back to gravel roads, now on the southern shore of the Rursee. There are also two climbs in this section. You will eventually climb along a stony asphalt road (the stones are well paved) through four hairpin bends, and suddenly the road turns into excellent asphalt. You will also pass a viewpoint with a wonderful view of the Rursee.
Please note: There is a sign at the beginning and end of a section of this asphalt road (see photo) indicating that this section is sensitive to falling trees and branches (due to drought and a beetle affecting the trees, branches can break off spontaneously even in the absence of wind). Finally, almost at the top of the Kermeter, the road really turns into gravel. Down the Kermeter it goes over the K7 (here only one bus comes), over excellent asphalt.

You switch back to gravel roads along the shores of Lake Urft and cross a bridge to the other bank and then climb steeply (16%) on asphalt road to Vogelsang Castle. You descend the plateau parallel to the B266 via a gravel bike path on the other side of a stream than the B266. This gravel bike path sometimes goes down steeply (up to 15%), there is even a piece of 23% gradient (indicated by a sign)!

At Einruhr you come briefly on the main road, but quickly dive into the Roertal via gravel roads. At Dedenborn, this turns into asphalt roads (Rurufer Radweg) and then it goes over gravel road into the Tiefenbach valley. At the oil mill, the gravel road becomes narrow, stony and it can get wet here because the stream can overflow its banks and because the streams drain from the slopes. One kilometer after the oil mill, this difficult passage in the Tiefenbach valley is over and the roads become gravel roads again.

Finally, you climb steeply out of the Tiefenbach valley partly over gravel and partly asphalt (max. 16%). You walk briefly through Simmerath and then change to a combination of asphalt and gravel roads in Upper Kalldal. Via Paustenbach you cycle to Lammersdorf, where you take a gravel road west of the village.

Gravel strips with their length in kilometers:

9.0 Forest area east of Lammersdorf +
Descent to the Kalltalsperre +
North/west bank of the Kalltalsperre
1.8 Descent through the Kall Valley
1.5 Continue to the Kalltal, immediately followed (without asphalt in between):
3.2 Ascent through the Fringsklafterbach valley (Attention: first half kilometre very stony, partly steep (up to 19%))
0.3 Neustraße (Schmidt)
3.4 Northern shore of the Rursee
7.3 South shore of Rursee + 1st part ascent Kermeter
0.9 kermeter
4.1 northern shore of Lake Urft
1.5 Vogelsang cycle path
4.7 Descent gravel cycle path (attention: partly steep up to 15%, one section 23%).
2.0 Rurtal
3.5 Tiefenbachtal (ascent). Please note: Part of the length of 1 km from the oil mill is a stony and narrow path
which can remain wet for some time after periods of rain.
0.8 last part Tiefenbachdal (with steep final section) - (more dirt road (cart road) than gravel road)
0.8 Kallerscheider Gasse
0.7 Upper Kall Valley
0.7 On fire
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46.2 km (= 61.3%) unpaved roads