ok mounted them and tried them out today , I left the rocker bolt as it was shipped so it had a nice flow to it and im not real heavy so it seemed to be a perfect fit I may even loosen it up a tad bit , I have to say these really feel great I don't play roller just ice so for me these are ideal for off ice training , ice time isn't always easy to get especially when the ice rinks schedule almost never lines up with mine lol,the shorter wheel base really gets the front wheel under the skate more barely even sticks out past the front of the skate , which for me made the balance point feel exactly like my ice skates , along with the rocker motion really made it feel more like ice skating , these are a great for someone looking to work on there ice skating when there is no ice time available , I have tried diff wheel set ups on my mission magnesium frames to get more of an ice skate feel and nothing I have tried has compared to the marsblade , I have not tried the sprungs so I cant comment on how they feel compared to those , hope this helps anyone who may be thinking of getting the marsblade set up , I would highly recommend them