I have a mini-club test track that includes 145mm radius curves, a turnout, a circuit track and an uncoupler to see how locos cope with these items.
The idea of an additional ‘running in’ track using a figure of eight appealed as it would obviously include left and right curves to give equal wear. To make it compact I have used Rokuhan 145mm radius curves and a 90 degree crossing (which Märklin don’t make, hence choice of Rokuhan) and a Rokuhan controller - although for anything other than can motored locos I have to use a normal mini-club controller as the Rokuhan will trip with the higher current that these 3 & 5 pole locos draw.
The relatively tight curves clean the wheels and conventional pickup wipers, from out of the box new you can see how the engines get smoother in a short time.
Drawback is - it is no good for the new designs which restrict the bogie movement such that they cannot negotiate the minimum radius of 145mm, but since those locos won’t run on my Tessein either there is not much point running them in.
Reading on this forum about ultra tiny screws to hold down Märklin mini-club track I tried to obtain some but the smallest I could find are Minitrix screws which happen to be ideal for Z gauge Rokuhan.
ChrisG

My simple warm up track, two lengths of Marklin 660mm silver soldered both sets of joints. Avoiding melting sleepers was a challenge. Slightly oval. Inside rail is cut shorter. Track glued to a piece of Forex (expanded PVC) with solvent.

I can't even sit a loco on the rails properly!


I replace the Marklin oil which turns into wax, with Faller oil 170489.

Maybe I should knock up something a bit more extravagant with all the pre-curved track I have replaced with 660mm lengths.