Some more about the ShroomBob™

Posted: Saturday, 22 October 2011 by Mark Kinnon in Labels: , ,

Robert Kolesar had a few additional comments about the recent post on the subject of the ShroomBob™
skibobs and skibikes.

The lift loading and unloading feature is the first unique feature of the Shroombob I  like to emphasize, as it greatly enhances ease of ski bike use, even for advanced riders who can carry the skibike in their lap or hooked onto the lift.  Not having to lift and carry the skibike while lift riding is really pretty cool and Our design completely compensates for the variability of lift seat height.

The second most important unique feature is the 4-bar suspension (a lever arm hinge mechanism - instead of direct connection - of the suspension arm and component to the frame of the skibike).  Have you ever ridden one of those really expensive bicycles at a local shop with this type of suspension?  Kona is the brand I use; it has 6 inches of seat travel through its suspension range, and can be ridden at speed directly into a curb from a street to a side walk (usually 6 - 8 inches) and make the transition feel smooth - like the curb is almost not there.  

The Shroombob has 8 inches of seat travel, and the 4-bar suspension is progressive, i.e. the more the suspension is deflected, the stiffer it becomes.  With this design bottoming out the suspension is impossible.  As the rider sits on the Shroombob, their weight alone depresses the suspension about 2-3 inches, and the sensation is like sitting on a soft lounge chair.  Using a suspension component with rebound control, the rider stays on the Shroombob almost automatically as the suspension smoothes out the ski terrain.  When riding at skibiking speeds into bumps, etc, the suspension does all the work of compensating (pre-jumping) the hazard.  The advantage of this suspension design, over traditional designs has to be ridden to be fully appreciated.  

The third most important unique feature of the Shroombob is a relative inability of the ski mount to rotate relative to the frame of the skibike.  This design allows the Shroombob suspension to drive the skis into the snow for turning and control, and allows the rider to use either the front or rear ski to carve turns. Also, the front ski does not dive into soft snow or powder, and tends to ride up out of these difficult snow conditions, instead of getting sucked in.