I test rode a friends Klein he wanted to sell me for a little over 500 miles, even swapped out the front wheel for mine and replace the tires, tubes and seat with mine. The deal was fantastic at $500 with less than 25 miles on it when I test rode it; but even though the thing would surge up hills, I felt more tired on it due to a buzzer and/or jarring ride. When I got back on my steel ride if felt much better and I did not feel as tired. If had wanted a racing machine I would have bought it, but I don't do that anymore.