Just got back from a show where Yamaha showed off the Vipers and thier new RX-1's. Had 4 colours though. Didn't know they came in black????? They had the silver one there also as a Mountain sled. 156 inch and they say it's 11 of travel. (Looks like more) 2 inch paddle track. Very Very quiet sled. Pretty cool. Thought I'd just share my experience of one.