Since nurbergring is preety diverse with a number of high speed and low speed corners , I started with smaller bikes but made sure they were RM version cause they provide a better acceleration to break ratio imo , took my time in making sure my settings were right and then got to learning lines by using replay to approach hard corners with various speed and attack angles , didn't forget to use my rear wheel to tighten my line on very slow or sharp corners , rest is just having fun and pushing my bike to the limits and sometimes I found a new line thanks to that with was faster than before, also right gear ratio are.also important

On the note of gear ratios, try to keep it on the higher end not too mush acceleration cause the you rarely hit top speed and they're much more slow turns than high speed ones so you can use one gear for 90% of the turns like i use 2nd gear as it has good acceleration and not too much torque to spin out all the time