After 4 months (approximately 30,000 reps) it was certainly defective. During training, the spring tension is broken, the rope is not pulled. At this point a big thank you to Amazon for easy return. All in all for the price (I paid then more than 200 Euro) a "okayes" rowing machine. More can I also do not think expect in the price range.
Now have "something" more money (approx. 1000) held in the hand and is investing in a Concept2 rowing machine. What can I say, feels as if you switch from a Fiat to a Porsche ... To be fair, I should mention that the price difference is accordingly! :)