After 2 years of owning my second gen Iron cobras I found that the drive shaft had so much lag it was creating a barrier for me with my double kick. I couldn't get anymore speed out of my left foot. So I was messing about at Long and Mcquade one day and found that I could put a Demon drive Z-Link on Iron cobras. so I placed an order for a Z-link and once it arrived I was amazed at the difference it made with my playing. I gained an amazing amount of speed and accuracy with my double kicks, and like the Demon drives my left pedal felt just like my right. It may have been costly ($130) but it was well worth it in the end!