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  A New Paradigm...

 

 

By: Rod Ratzlaff

Jeffrey Rapp at speed on a bike of his own creation...

February 2018

     I recently had the chance to get in a couple hours of saddle time on the new Boomerang skibike at Beaver Creek, Colorado. This was a much anticipated demo, as I had been conversing digitally with the builder for about a year. I have always been attracted by uniqueness and originality in design, so this bike definitely had my attention. Of course, the most unique factor is the utilization of a single bike-ski, this is the first production mono-ski skibike for the masses. This was a chance for a fresh, novel experience, and I was very curious as to the handling characteristics of this new creation.

     The builder is Jeffrey Rapp, an Adaptive rider from Louisiana. He had been modifying existing 2-ski bikes since 2004 to accommodate his need for an auto-lift loading frame design (see photo at bottom  of page). He was looking for better ride quality, and to simplify ski attachment and increase ski length. These aspirations eventually led to the beginning of the prototyping process for the mono-ski concept in 2014 (see photo at bottom  of page). The rather long commute from Louisiana to ski  prompted the purchase of a condo in Colorado, making the slope-testing process much more convenient. The end result of that process is these bikes:

    

     

     

     

    

 

 

 

=TECHNICAL...

    *The bike is available in two versions, box frame (left) and tube frame (right). *It is designed to be ridden with foot-skis. *Standard alpine bike-skis (w/standard bindings) are utilized, ski mount position is adjustable 5". Typical ski lengths: 165-185cm. *Shock absorbers are Fox FLOAT 3 EVOL R snowmobile air shocks of varying lengths providing up to 22" of suspension travel! Shock mounting is 6-way adjustable for seat height, which is variable from aprox 26" to 36" (uncompressed). *Handlebars are exchangeable. *Foot-rests and foot-skis are optional. *The box frame model features a storage compartment.

SPECS:

*Category... Adult All Mountain  *Model(s)... 2  *Weight... 18# / 21# w/o skis  *Suspension... Adjustable Air Shock  *Frame... Aluminum   *Bike-ski...Variable  *Foot-skis...Variable  *Options... Foot-rests, Foot-skis  *Warranty... 2 years  *Retail... TBA- expected to be comparable with mid to upper end skibobs. *MFG... USA

 

=SLOPE TEST...

    I rode the tube frame version of the bike, which is my personal preference. It's simpler, smaller and lighter. It was set up with relatively short, soft 166cm skis. The 17.5" shock provided about 16" of actual suspension travel.

     Since I am acclimated to a standard 2-ski bike, the first impression is the strange sensation of handlebars that don't turn! That definitely takes some getting used to... Another unaccustomed feature is seating, static seat height started out tall, but weighted it was set to sag 8" to about standard skibob height. Hmmm... This is all adjustable, but more on that later.

    The first order of  business, the lift. We've all experienced the logistical maneuvering required to lift-load a skibike. What if all of that could be eliminated? One of the primary design concepts of this frame is to simplify this process. And, simple it is. You stand straddling the bike in the load location, the chair then scoops up the bike and you along with it. With some maneuvering, the safety bar can then be deployed. You then cruise up the mountain sitting on the bike seat. No leash should be required by the resort, the bike is absolutely secure. To unload, just reverse the sequence, stand up and push away. An elegant solution, I have only one thing to say — m-a-r-v-e-l-o-u-s. . .

     Once out on the slope, the lesson begins. Without the accustomed counter-steering effect of a 2-ski bike, making turns initially seemed ponderous. But, I soon realized that the trick (for me) was to use all that suspension travel to pogo and weight/un-weight the ski in turns, just like regular alpine skiing. I even tried standing up on the foot-skis and swinging the tail back and forth, an interesting sensation.

Other Impressions:

     My time in the saddle was limited, and spent on mild green/blue slopes. Consequently, this appraisal should be considered preliminary...

*Turns > Once you figure out the technique, the bike will edge/carve competently. I was impressed at how well it would hold a line in icy conditions. Skidded turns were also smooth and predicable.

*Stability/Tracking > Good, it seemed to hold a line well at moderate/medium speeds.

* Powder > I only had a brief opportunity on an un-groomed section, just a few inches deep but it seemed to handle it without issue. Deep powder would require a longer/wider ski.

* Technical -Trees/Moguls/Jumps/Steeps > I didn't have a chance to conduct an intricate evaluation on these types of terrain. I did jump in and out quickly on some short tree trails parallel to the slopes, with a couple of small jumps thrown in. I would prophesize that tight deep-woods riding is not the strong suit of this design, likewise for moguls. Jumps could be interesting, the long-travel suspension could be quite advantageous. I think it would require a longer, stiffer ski. It seemed to have a tendency to pitch forward on the jumps I tried, although more familiarity with the balance characteristics (and adjustment thereof) should yield improved results.  

* Misc > The seat was comfortable, and the ergonomics were good. And, with all that suspension travel, the ride was plush. My back and posterior were appreciative of that characteristic...

    The bike has a very wide range of adjustability: The air-suspension setup is almost infinitely variable, and the ski mount position can be altered 5" fore and aft for balance. This is a critical factor on a mono-ski design, as is ski selection, which is also easily modifiable. The bike can be custom-tailored to suit about any riding style, although experimentation with all of those possible settings could make getting it dialed in perfectly a rather time consuming process.

 

=Synopsis...

     I feel that the Boomerang Mono-Bike provides several advantages over the prevailing 2-ski offerings:

*Number one is the auto lift-load feature, this is essential for some adaptive riders, and just very convenient for the rest of us. *The suspension is in a league of it's own with massive travel. *The utilization of  a standard alpine quick-change binding opens up a plethora of options in ski selection, used downhill skis are very widely available at bargain prices. This feature also allows the ski to be easily removed for transportation purposes. *Another attribute is the light weight, only 18 lbs for the tube frame model, plus a ski. Typically, a ski and binding will add 4-6 lbs. *And last, but not least, is the uniqueness and originality of the Mono-Ski design, you'll definitely stand out in the crowd.

     The spirit of innovation is truly alive and well in the USA... This is a very credible addition to the skibike universe.

 

     ~As of the date of this article, bikes have been placed in various ski area instructional programs for evaluation. They are expected to be generally available for purchase in the 2018-2019 season.  www.boomerangskibikes.com

    

     

 

An auto- lift load conversion kit on a Brenter C-6...

The first Mono-Bike prototype...